A special issue of Biophysical Reviews dedicated to the 20th IUPAB (virtual) Congress “in” Foz do Iguaçu

The 20th IUPAB Congress took place online, together with the annual meetings of the Brazilian Biophysical Society and the Brazilian Society for Biochemistry and Molecular Biology, from the 4th to the 8th of October, 2021. The ten keynote lectures, 24 symposia, two poster sessions, and a series of technical seminars covered the full diversity of current biophysical research and its interfaces with other fields. The event had over 1000 attendees, with an excellent gender balance. Although the Americas dominated, there were also significant numbers of participants from Europe, Asia, and Africa.

The International Union of Pure and Applied Biophysics (IUPAB) came into existence in Stockholm in 1961 and has been a member of the International Science Council since 1966 (Solomon 1968). Its overall objectives aim to foster international collaboration in all aspects of biophysics and related areas and to catalyze the advancement of basic biophysical research as well as its many applications. Although IUPAB is active on many fronts, undeniably one of its showcase events is the IUPAB Congress, traditionally organized every three years in different locations worldwide. In 2021, the event was organized and run from Brazil, albeit for the very first time in a virtual format due to travel restrictions imposed by the COVID-19 pandemic. On this occasion, the Congress was organized in conjunction with the annual meetings of both the Brazilian Biophysical Society (SBBf, in its 45th edition) and the Brazilian Society for Biochemistry and Molecular Biology (SBBq, in its 50th edition). Even with the united forces of these well-established local societies, it turned out to be a bumpy ride to bring the event to fruition.Plans for the 20th Congress began in 2016, almost immediately after the decision to hold the event in Brazil, a cause championed by the then-president of the Brazilian Biophysical Society, Marcelo Morales. The original plans had the meeting to be held in the Cidade Maravilhosa (The Wonderful City) of Rio de Janeiro in October 2020. However, it soon became apparent that the political and economic difficulties that the State of Rio was facing at the time meant that it would be wise to search for an alternative venue. The previous experience of SBBq in organizing similar events in the city of Foz do Iguaçu, on the borders with Argentina and Paraguay, made this an obvious choice. Furthermore, the natural attraction of the spectacular Iguaçu waterfalls seemed to be an ideal compensation for Sugar Loaf Mountain, Copacabana beach, and the statue of Christ the Redeemer on Corcovado Mountain.Then came the pandemic. By mid-2020, it had become apparent that there were too many unknowns to make it possible to proceed with an in-person event in October of that year. It was decided to postpone the congress to 2021 but with a firm belief that things would be “back to normal.” Sweet delusion! As 2020 turned into 2021 and the severity and longevity of the pandemic became clearer and clearer (not to mention the abysmal performance of the Brazilian government in failing to rise to the challenge), the inevitable decision was taken to transform the event into an “on-line” congress. This was a first for both the local organizers and the IUPAB.The move to an online format immediately had an impact on the organization of the Young Scientist Program. This was initially envisaged to be a combination of formal and informal activities aimed at uniting about 40 early carrier scientists and post-docs for a couple of days prior to the main event in a stimulating atmosphere conducive to networking. Skillfully conceived, organized, and executed by Eneida de Paula (Campinas) and Eduardo Reis (São Paulo), this too had to be adapted to a “virtual reality.” The successful solution turned out to be a series of fortnightly thematic webinars, including a talk from a recognized authority in the field followed by three or four short presentations from the participants themselves (Table ​(Table1).1). The standard was extremely high and the YSP ended up being a highly effective warm-up to the congress itself. Furthermore, there was excellent geographical diversity among the participants with Europe, Africa, Asia, the Middle East, and both North and South America represented.Table 1Young Scientist Webinar Program

P‐1DIRECT‐TO‐VIAL USE OF THE LIQUI‐PREP™ CYTOLOGY SYSTEM

Introduction: The authors initiated the use of Liqui‐PREP? (LGM International Inc., Fort Lauderdale, FL, USA) in August, 2005. Cytotechnologists received extensive (one month) training by cytopathologists experienced in Liquid‐based cytology. The Liqui‐PREP? direct‐to‐vial procedure (LP) was compared to the conventional Pap smears in a routine screening population. Methods: Data derived from 26 178 LP cervical‐vaginal (CV) specimens were compared to data derived from 218 548 conventional Pap smears (CS). Both data sets reflect patient samples collected concurrently (August–December, 2005) by 117 participating outpatient medical practices from a well‐defined geographic area. There were no significant personnel changes during the study period. The diagnostic results, classified according to Bethesda criteria were calculated. Results:

SEAWEED EXTRACTS AS A POTENTIAL TOOL FOR THE ATTENUATION OF OXIDATIVE DAMAGE IN OBESITY‐RELATED PATHOLOGIES1

Recent studies suggest that seaweed extracts are a significant source of bioactive compounds comparable to the dietary phytochemicals such as onion and tea extracts. The exploration of natural antioxidants that attenuate oxidative damage is important for developing strategies to treat obesity‐related pathologies. The objective of this study was to screen the effects of seaweed extracts of 49 species on adipocyte differentiation and reactive oxygen species (ROS) production during the adipogenesis in 3T3‐L1 adipocytes, and to investigate their total phenol contents and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging activities. Our results show that high total phenol contents were observed in the extracts of Ecklonia cava (see Table 1 for taxonomic authors) (681.1 ± 16.0 μg gallic acid equivalents [GAE] · g^?1), Dictyopteris undulata (641.3 ± 70.7 μg GAE · g^?1), and Laurencia intermedia (560.9 ± 48.1 μg GAE · g^?1). In addition, DPPH radical scavenging activities were markedly higher in Sargassum macrocarpum (60.2%), Polysiphonia morrowii (55.0%), and Ishige okamurae (52.9%) than those of other seaweed extracts (P < 0.05). Moreover, treatment with several seaweed extracts including D. undulata, Sargassum micracanthum, Chondrus ocellatus, Gelidium amansii, Gracilaria verrucosa, and Grateloupia lanceolata significantly inhibited adipocyte differentiation and ROS production during differentiation of 3T3‐L1 preadipocytes. Furthermore, the production of ROS was positively correlated with lipid accumulation (R² = 0.8149). According to these preliminary results, some of the seaweed extracts can inhibit ROS generation, which may protect against oxidative stress that is linked to obesity. Further studies are required to determine the molecular mechanism between the verified seaweeds and ROS, and the resulting effects on obesity.

Table 1. List of Korean seaweed extracts of 49 species evaluated in this experiment.

Calorimetric determination of base-stacking enthalpies in double-helical DNA molecules

Differential scanning calorimetry was used to directly determine the transition enthalpies accompanying the duplex-to-single-strand transition of poly[d(AT)], poly(dA)·poly(dT), poly[d(AC)]·poly[d(TG)], and d(GCGCGC). The calorimetric data allow us to define the following average base-stacking enthalpies:

Comparison of the Efficacy of the Two Tetracycline‐Containing Sequential Therapy Regimens for the Eradication of Helicobacter Pylori: 5 days Versus 14 days Amoxicillin

Aim: To compare the efficacy of 14‐day and 5‐day amoxicillin treatment on the eradication rate during tetracycline containing sequential H. pylori therapy, and also to compare the eradication rate of this regimen with those used in similar studies performed in Turkey. Method: This study included 112 patients infected with H. pylori that were randomized into 2 groups. In group A, patients (n = 56) received pantoprazole (40 mg BID) and amoxicillin (1 g BID) for 5 days, followed by pantoprazole (40 mg BID), tetracycline (500 mg QID), and metronidazole (500 mg TID) for the remaining 9 days. In group B, patients (n = 56) received pantoprazole (40 mg BID) and amoxicillin (1 g BID) for 5 days, followed by pantoprazole (40 mg BID), tetracycline (500 mg QID), metronidazole (500 mg TID), and amoxicillin (1 g BID) for the remaining 9 days. Eradication rates were calculated using both intention‐to‐treat (ITT) and per‐protocol (PP) analyses. Results: In all, 112 patients were subjected to ITT analysis and 109 patients completed the study. In group A, H. pylori eradication was achieved in 46 (82.1%) of the 56 patients included in the ITT analysis and in 46 (83.6%) of the 55 patients included in the PP analysis. In group B, H. pylori eradication was achieved in 44 (78.57%) of the 56 patients included in the ITT analysis and in 44 (81.48%) of the 54 patients included in the PP analysis ( Table 2 ). The eradication rates were not statistically significant between the 2 groups (p > .005).

Table 2. Eradication rates in the two study groups

Posters. P9 A case of carcinosarcoma presenting in a cervical ThinPrep® sample

Introduction Direct endometrial sampling with cytology and or histology is used at our hospital as part of the investigation of abnormal uterine bleeding. It is used in cases where there is a low clinical suspicion of malignancy. The advantage of the technique is that it can be done as an outpatient procedure with minimal patient discomfort. Reports in the literature give mixed results. We present a 3‐year retrospective of our experience with follow‐up.

Pre-dispersal seed predation and seed limitation in an annual legume

The basic idea of the source simulation technique is to replace the scatterer (or radiator by a system of simple sources located within the envelope of the original body. The extent to which the simulated field reproduces the original field depends on the degree of correspondence between the simulated and the given boundary conditions. Numerical simulations have shown that: (1) the shape of the auxiliary surface, (2) the number of sources, and (3) the way the sources are distributed are the most relevant parameters to ensure an accurate solution for the problem. In the case of the single-layer method, sources should not be positioned close to the center of the body, because the problem becomes ill-conditioned. The auxiliary surface and the scatterer should be as similar as possible in order to minimize the boundary error. With respect to the number of sources (N), there are two opposite effects: (1) if (N) is too small, the sound field is not reproduced accurately; (2) if (N) is too large, computing time increases and solution accuracy decreases. The method beaks down when excitation frequency coincides with the eigenfrequencies — a narrow range of frequencies — of the space formed by the auxiliary surface. As the auxiliary surface is frequently represented by simple surfaces (cylinder, sphere), one can easily calculate the eigenfrequencies and therefore avoid them.

Endoplasmic Reticulum Targeting and Insertion of Tail-Anchored Membrane Proteins by the GET Pathway

Hundreds of eukaryotic membrane proteins are anchored to membranes by a single transmembrane domain at their carboxyl terminus. Many of these tail-anchored (TA) proteins are posttranslationally targeted to the endoplasmic reticulum (ER) membrane for insertion by the guided-entry of TA protein insertion (GET) pathway. In recent years, most of the components of this conserved pathway have been biochemically and structurally characterized. Get3 is the pathway-targeting factor that uses nucleotide-linked conformational changes to mediate the delivery of TA proteins between the GET pretargeting machinery in the cytosol and the transmembrane pathway components in the ER. Here we focus on the mechanism of the yeast GET pathway and make a speculative analogy between its membrane insertion step and the ATPase-driven cycle of ABC transporters.The mechanism of membrane protein insertion into the endoplasmic reticulum (ER) has been extensively studied for many years (Shao and Hegde 2011). From this work, the signal recognition particle (SRP)/Sec61 pathway has emerged as a textbook example of a cotranslational membrane insertion mechanism (Grudnik et al. 2009). The SRP binds a hydrophobic segment (either a cleavable amino-terminal signal sequence or a transmembrane domain) immediately after it emerges from the ribosomal exit tunnel. This results in a translational pause that persists until SRP engages its receptor in the ER and delivers the ribosome-nascent chain complex to the Sec61 channel. Last, the Sec61 channel enables protein translocation into the ER lumen along with partitioning of hydrophobic transmembrane domains into the lipid bilayer through the Sec61 lateral gate (Rapoport 2007).Approximately 5% of all eukaryotic membrane proteins have an ER targeting signal in a single carboxy-terminal transmembrane domain that emerges from the ribosome exit tunnel following completion of protein synthesis and is not recognized by the SRP (Stefanovic and Hegde 2007). Nonetheless, because hydrophobic peptides in the cytoplasm are prone to aggregation and subject to degradation by quality control systems (Hessa et al. 2011), these tail-anchored (TA) proteins still have to be specifically recognized, shielded from the aqueous environment, and guided to the ER membrane for insertion. In the past five years, the guided-entry of TA proteins (GET) pathway has come to prominence as the major machinery for performing these tasks and the enabler of many key cellular processes mediated by TA proteins including vesicle fusion, membrane protein insertion, and apoptosis. This research has rapidly yielded biochemical and structural insights (​and2)2) into many of the GET pathway components (Hegde and Keenan 2011; Chartron et al. 2012a; Denic 2012). In particular, Get3 is an ATPase that uses metabolic energy to bridge recognition of TA proteins by upstream pathway components with TA protein recruitment to the ER for membrane insertion. However, the precise mechanisms of nucleotide-dependent TA protein binding to Get3 and how the GET pathway inserts tail anchors into the membrane are still poorly understood. Here, we provide an overview of the budding yeast GET pathway with emphasis on mechanistic insights that have come from structural studies of its membrane-associated steps and make a speculative juxtaposition with the ABC transporter mechanism.

Table 1.

A catalog of GET pathway component structures

Proffered Papers 10.30–11.15 Monday 15 September 2003 3 5 year outcome of women with borderline and mild dyskaryosis smears 3 5 year outcome of women with borderline and mild dyskaryosis smears

Aims

• 1 To identify the outcome status of women with borderline and mild dyskaryosis smears.
• 2 To determine whether the presence or absence of koilocytosis influences the outcome status.
• 3 To identify the proportion of women with borderline smears showing koilocytosis.

Materials and methods Borderline and mild dyskaryosis cervical smears diagnosed during January to March 1997 were identified from the laboratory database. Each slide was reviewed by two researchers independently, who then agreed a final consensus diagnosis. All slides were classified according to the presence or absence of koilocytosis. Slides were excluded from the study if the review diagnosis was negative, inadequate or high‐grade dyskaryosis. The outcome status was classified according to the worst lesion identified histologically and/or cytologically during the 5‐year follow‐up period. Results 1974 women were identified with borderline or mild dyskaryosis cervical smears of which 1597 were included in the study. Table 1 shows the outcome status of these women.

Table 1. . The outcome status of these women

Reproductive potential and endocrinological responses of sheep kept under controlled lighting. I. Comparative reproductive performance of four breed types of ewe

Five ewes of each of four breed types were kept in each of two environmentally-controlled rooms over a period of 2.5 years. The daylength varied between 20 and 9 h on a 6-monthly cycle, including a period of 22 weeks during which daylength was decreased by 0.5 h per week, 2 weeks in which it increased from 9 to 20 h, and 2 weeks at 20 h; each room operated 3 months out of phase with the other. Towards the end of the period of decreasing daylength each ewe was synchronised with a progestagen sponge for 12 days, given an injection (i.m.) of 750 I.U. pregnant mares' serum gonadotrophin (PMSG) on withdrawal, and inseminated 48 and 58 h later (500 million fresh undiluted sperm per insemination). Thus, insemination occurred at a single synchronised oestrus every 6 months. Progesterone pregnancy diagnosis was performed on blood samples taken 18 days later and parturition was induced by an injection (i.m.) of 16 mg dexamethasone on day 143 of gestation. Lambs were weaned at birth, allowing the ewes approximately 5.5 weeks to recover before the next insemination and a ‘successive’ conception.The performance of the four types of ewe, starting as maidens, is tabulated.

     

18.

Association of Campylobacter jejuni Cj0859c Gene (fspA) Variants with Different C. jejuni Multilocus Sequence Types     

C. P. A. de Haan  R. Kivist?  M. L. H?nninen 《Applied and environmental microbiology》2010,76(20):6942-6943

Cj0859c variants fspA1 and fspA2 from 669 human, poultry, and bovine Campylobacter jejuni strains were associated with certain hosts and multilocus sequence typing (MLST) types. Among the human and poultry strains, fspA1 was significantly (P < 0.001) more common than fspA2. FspA2 amino acid sequences were the most diverse and were often truncated.Campylobacter jejuni is the leading cause of bacterial gastroenteritis worldwide and responsible for more than 90% of Campylobacter infections (7). Case-control studies have identified consumption or handling of raw and undercooked poultry meat, drinking unpasteurized milk, and swimming in natural water sources as risk factors for acquiring domestic campylobacteriosis in Finland (7, 9). Multilocus sequence typing (MLST) has been employed to study the molecular epidemiology of Campylobacter (4) and can contribute to virulotyping when combined with known virulence factors (5). FspA proteins are small, acidic, flagellum-secreted nonflagellar proteins of C. jejuni that are encoded by Cj0859c, which is expressed by a σ²⁸ promoter (8). Both FspA1 and FspA2 were shown to be immunogenic in mice and protected against disease after challenge with a homologous strain (1). However, FspA1 also protected against illness after challenge with a heterologous strain, whereas FspA2 failed to do the same at a significant level. Neither FspA1 nor FspA2 protected against colonization (1). On the other hand, FspA2 has been shown to induce apoptosis in INT407 cells, a feature not exhibited by FspA1 (8). Therefore, our aim was to study the distributions of fspA1 and fspA2 among MLST types of Finnish human, chicken, and bovine strains.In total, 367 human isolates, 183 chicken isolates, and 119 bovine isolates (n = 669) were included in the analyses (3). PCR primers for Cj0859c were used as described previously (8). Primer pgo6.13 (5′-TTGTTGCAGTTCCAGCATCGGT-3′) was designed to sequence fspA1. Fisher''s exact test or a chi-square test was used to assess the associations between sequence types (STs) and Cj0859c. The SignalP 3.0 server was used for prediction of signal peptides (2).The fspA1 and fspA2 variants were found in 62.6% and 37.4% of the strains, respectively. In 0.3% of the strains, neither isoform was found. Among the human and chicken strains, fspA1 was significantly more common, whereas fspA2 was significantly more frequent among the bovine isolates (Table ​(Table1).1). Among the MLST clonal complexes (CCs), fspA1 was associated with the ST-22, ST-45, ST-283, and ST-677 CCs and fspA2 was associated with the ST-21, ST-52, ST-61, ST-206, ST-692, and ST-1332 CCs and ST-58, ST-475, and ST-4001. Although strong CC associations of fspA1 and fspA2 were found, the ST-48 complex showed a heterogeneous distribution of fspA1 and fspA2. Most isolates carried fspA2, and ST-475 was associated with fspA2. On the contrary, ST-48 commonly carried fspA1 (Table ​(Table1).1). In our previous studies, ST-48 was found in human isolates only (6), while ST-475 was found in both human and bovine isolates (3, 6). The strict host associations and striking difference between fspA variants in human ST-48 isolates and human/bovine ST-475 isolates suggest that fspA could be important in host adaptation.

TABLE 1.

Percent distributions of fspA1 and fspA2 variants among 669 human, poultry, and bovine Campylobacter jejuni strains and their associations with hosts, STs, and CCs

Conceptions	Merino	Dorset Horn × Merino	Border Leic. × Merino	South Suffolk × Merino	$\text{P}$
Successive (%)	20.0	12.5	11.1	47.6	$\text{< 0.01}$
Non-successive (%)	76.0	76.9	66.7	95.0	$\text{< 0.05}$
Overall (%)	51.1	52.4	44.4	70.7	$\text{< 0.05}$
Mean litter size	1.7	1.5	1.5	2.2	$\text{< 0.05}$
Mean lambs per ewe per year	1.8	1.6	1.3	3.1	$\text{< 0.01}$

Host or ST complex/ST (no. of isolates)	% of strains witha:		P valueb
	fspA1	fspA2
Host
All (669)	64.3	35.4
Human (367)	69.5	30.0	<0.001
Poultry (183)	79.2	20.8	<0.001
Bovine (119)	25.2	74.8	<0.0001
ST complex and STs
ST-21 complex (151)	2.6	97.4	<0.0001
ST-50 (76)	NF	100	<0.0001
ST-53 (19)	NF	100	<0.0001
ST-451 (9)	NF	100	<0.0001
ST-883 (11)	NF	100	<0.0001
ST-22 complex (22)	100	NF	<0.0001
ST-22 (11)	100	NF	<0.01
ST-1947 (9)	100	NF	0.03
ST-45 complex (268)	99.3	0.7	<0.0001
ST-11 (7)	100	NF	NA
ST-45 (173)	99.4	0.6	<0.0001
ST-137 (22)	95.5	4.5	0.001
ST-230 (14)	100	NF	<0.0001
ST-48 complex (18)	44.4	55.6	NA
ST-48 (7)	100	NF	NA
ST-475 (8)	NF	100	<0.001
ST-52 complex (5)	NF	100	<0.01
ST-52 (4)	NF	100	0.02
ST-61 complex (21)	NF	100	<0.0001
ST-61 (11)	NF	100	<0.0001
ST-618 (3)	NF	100	0.04
ST-206 complex (5)	NF	100	<0.01
ST-283 complex (24)	100	NF	<0.0001
ST-267 (23)	100	NF	<0.0001
ST-677 complex (59)	100	NF	<0.0001
ST-677 (48)	100	NF	<0.0001
ST-794 (11)	100	NF	<0.001
ST-692 complex (3)	NF	100	0.04
ST-1034 complex (5)	NF	80	NA
ST-4001 (3)	NF	100	0.04
ST-1287 complex/ST-945 (8)	100	NF	NA
ST-1332 complex/ST-1332 (4)	NF	100	0.02
Unassigned STs
ST-58 (6)	NF	100	<0.01
ST-586 (6)	100	NF	NA

Open in a separate window^aIn 0.3% of the strains, neither isoform was found. NF, not found.^bNA, not associated.A total of 28 isolates (representing 6 CCs and 13 STs) were sequenced for fspA1 and compared to reference strains NCTC 11168 and 81-176. All isolates in the ST-22 CC showed the same one-nucleotide (nt) difference with both NCTC 11168 and 81-176 strains, resulting in a Thr→Ala substitution in the predicted protein sequence (represented by isolate FB7437, GenBank accession number {"type":"entrez-nucleotide","attrs":{"text":"HQ104931","term_id":"311102197"}}HQ104931; Fig. ​Fig.1).1). Eight other isolates in different CCs showed a 2-nt difference (isolate 1970, GenBank accession number {"type":"entrez-nucleotide","attrs":{"text":"HQ104932","term_id":"311102199"}}HQ104932; Fig. ​Fig.1)1) compared to strains NCTC 11168 and 81-176, although this did not result in amino acid substitutions. All 28 isolates were predicted to encode a full-length FspA1 protein.Open in a separate windowFIG. 1.Comparison of FspA1 and FspA2 isoforms. FspA1 is represented by 81-176, FB7437, and 1970. FspA2 is represented by C. jejuni strains 76763 to 1960 (GenBank accession numbers {"type":"entrez-nucleotide-range","attrs":{"text":"HQ104933 to HQ104946","start_term":"HQ104933","end_term":"HQ104946","start_term_id":"311102201","end_term_id":"311102227"}}HQ104933 to HQ104946). Scale bar represents amino acid divergence.In total, 62 isolates (representing 7 CCs and 35 STs) were subjected to fspA2 sequence analysis. Although a 100% sequence similarity between different STs was found for isolates in the ST-21, ST-45, ST-48, ST-61, and ST-206 CCs, fspA2 was generally more heterogeneous than fspA1 and we found 13 predicted FspA2 amino acid sequence variants in total (Fig. ​(Fig.1).1). In several isolates with uncommon and often unassigned (UA) STs, the proteins were truncated (Fig. ​(Fig.1),1), with most mutations being ST specific. For example, all ST-58 isolates showed a 13-bp deletion (isolate 3074_2; Fig. ​Fig.1),1), resulting in a premature stop codon. Also, all ST-1332 CC isolates were predicted to have a premature stop codon by the addition of a nucleotide between nt 112 and nt 113 (isolate 1960; Fig. ​Fig.1),1), a feature shared with two isolates typed as ST-4002 (UA). A T68A substitution in ST-1960 (isolate T-73494) also resulted in a premature stop codon. Interestingly, ST-1959 and ST-4003 (represented by isolate 4129) both lacked one triplet (nt 235 to 237), resulting in a shorter FspA2 protein. SignalP analysis showed the probability of a signal peptide between nt 22 and 23 (ACA-AA [between the underlined nucleotides]). An A24C substitution in two other strains, represented by isolate 76580, of ST-693 and ST-993 could possibly result in a truncated FspA2 protein as well.In conclusion, our results showed that FspA1 and FspA2 showed host and MLST associations. The immunogenic FspA1 seems to be conserved among C. jejuni strains, in contrast to the heterogeneous apoptosis-inducing FspA2, of which many isoforms were truncated. FspA proteins could serve as virulence factors for C. jejuni, although their roles herein are not clear at this time.     

Association of Campylobacter jejuni Cj0859c Gene (fspA) Variants with Different C. jejuni Multilocus Sequence Types

Cj0859c variants fspA1 and fspA2 from 669 human, poultry, and bovine Campylobacter jejuni strains were associated with certain hosts and multilocus sequence typing (MLST) types. Among the human and poultry strains, fspA1 was significantly (P < 0.001) more common than fspA2. FspA2 amino acid sequences were the most diverse and were often truncated.Campylobacter jejuni is the leading cause of bacterial gastroenteritis worldwide and responsible for more than 90% of Campylobacter infections (7). Case-control studies have identified consumption or handling of raw and undercooked poultry meat, drinking unpasteurized milk, and swimming in natural water sources as risk factors for acquiring domestic campylobacteriosis in Finland (7, 9). Multilocus sequence typing (MLST) has been employed to study the molecular epidemiology of Campylobacter (4) and can contribute to virulotyping when combined with known virulence factors (5). FspA proteins are small, acidic, flagellum-secreted nonflagellar proteins of C. jejuni that are encoded by Cj0859c, which is expressed by a σ²⁸ promoter (8). Both FspA1 and FspA2 were shown to be immunogenic in mice and protected against disease after challenge with a homologous strain (1). However, FspA1 also protected against illness after challenge with a heterologous strain, whereas FspA2 failed to do the same at a significant level. Neither FspA1 nor FspA2 protected against colonization (1). On the other hand, FspA2 has been shown to induce apoptosis in INT407 cells, a feature not exhibited by FspA1 (8). Therefore, our aim was to study the distributions of fspA1 and fspA2 among MLST types of Finnish human, chicken, and bovine strains.In total, 367 human isolates, 183 chicken isolates, and 119 bovine isolates (n = 669) were included in the analyses (3). PCR primers for Cj0859c were used as described previously (8). Primer pgo6.13 (5′-TTGTTGCAGTTCCAGCATCGGT-3′) was designed to sequence fspA1. Fisher''s exact test or a chi-square test was used to assess the associations between sequence types (STs) and Cj0859c. The SignalP 3.0 server was used for prediction of signal peptides (2).The fspA1 and fspA2 variants were found in 62.6% and 37.4% of the strains, respectively. In 0.3% of the strains, neither isoform was found. Among the human and chicken strains, fspA1 was significantly more common, whereas fspA2 was significantly more frequent among the bovine isolates (Table ​(Table1).1). Among the MLST clonal complexes (CCs), fspA1 was associated with the ST-22, ST-45, ST-283, and ST-677 CCs and fspA2 was associated with the ST-21, ST-52, ST-61, ST-206, ST-692, and ST-1332 CCs and ST-58, ST-475, and ST-4001. Although strong CC associations of fspA1 and fspA2 were found, the ST-48 complex showed a heterogeneous distribution of fspA1 and fspA2. Most isolates carried fspA2, and ST-475 was associated with fspA2. On the contrary, ST-48 commonly carried fspA1 (Table ​(Table1).1). In our previous studies, ST-48 was found in human isolates only (6), while ST-475 was found in both human and bovine isolates (3, 6). The strict host associations and striking difference between fspA variants in human ST-48 isolates and human/bovine ST-475 isolates suggest that fspA could be important in host adaptation.

TABLE 1.

Percent distributions of fspA1 and fspA2 variants among 669 human, poultry, and bovine Campylobacter jejuni strains and their associations with hosts, STs, and CCs

Mechanisms and Evidence of Genital Coevolution: The Roles of Natural Selection,Mate Choice,and Sexual Conflict

Genital coevolution between the sexes is expected to be common because of the direct interaction between male and female genitalia during copulation. Here we review the diverse mechanisms of genital coevolution that include natural selection, female mate choice, male–male competition, and how their interactions generate sexual conflict that can lead to sexually antagonistic coevolution. Natural selection on genital morphology will result in size coevolution to allow for copulation to be mechanically possible, even as other features of genitalia may reflect the action of other mechanisms of selection. Genital coevolution is explicitly predicted by at least three mechanisms of genital evolution: lock and key to prevent hybridization, female choice, and sexual conflict. Although some good examples exist in support of each of these mechanisms, more data on quantitative female genital variation and studies of functional morphology during copulation are needed to understand more general patterns. A combination of different approaches is required to continue to advance our understanding of genital coevolution. Knowledge of the ecology and behavior of the studied species combined with functional morphology, quantitative morphological tools, experimental manipulation, and experimental evolution have been provided in the best-studied species, all of which are invertebrates. Therefore, attention to vertebrates in any of these areas is badly needed.Of all the evolutionary interactions between the sexes, the mechanical interaction of genitalia during copulation in species with internal fertilization is perhaps the most direct. For this reason alone, coevolution between genital morphologies of males and females is expected. Morphological and genetic components of male and female genitalia have been shown to covary in many taxa (Sota and Kubota 1998; Ilango and Lane 2000; Arnqvist and Rowe 2002; Brennan et al. 2007; Rönn et al. 2007; Kuntner et al. 2009; Tatarnic and Cassis 2010; Cayetano et al. 2011; Evans et al. 2011, 2013; Simmons and García-González 2011; Yassin and Orgogozo 2013; and see examples in TaxaMale structuresFemale structuresEvidenceLikely mechanismReferencesMollusks Land snails (Xerocrassa)Spermatophore-producing organsSpermatophore-receiving organsComparative among speciesSAC or female choiceSauder and Hausdorf 2009 SatsumaPenis lengthVagina lengthCharacter displacementLock and keyKameda et al. 2009Arthropods Arachnids (Nephilid spiders)MultipleMultipleComparative among speciesSACKuntner et al. 2009 Pholcidae spidersCheliceral apophysisEpigynal pocketsComparative (no phylogenetic analysis)Female choiceHuber 1999 Harvestmen (Opiliones)Hardened penes and loss of nuptial giftsSclerotized pregenital barriersComparative among speciesSACBurns et al. 2013Millipedes Parafontaria tonomineaGonopod sizeGenital segment sizeComparative in species complexMechanical incompatibility resulting from Intersexual selectionSota and Tanabe 2010 Antichiropus variabilisGonopod shape and sizeAccesory lobe of the vulva and distal projectionFunctional copulatory morphologyLock and keyWojcieszek and Simmons 2012Crustacean Fiddler crabs, UcaGonopodeVulva, vagina, and spermathecaTwo-species comparison, shape correspondenceNatural selection against fluid loss, lock and key, and sexual selectionLautenschlager et al. 2010Hexapodes OdonatesClasping appendagesAbdominal shape and sensory hairsFunctional morphology, comparative among speciesLock and key via female sensory systemRobertson and Paterson 1982; McPeek et al. 2009Insects Coleoptera: seed beetlesSpiny aedagusThickened walls of copulatory ductComparative among speciesSACRönn et al. 2007 Callosobruchus: Callosobruchus maculatusDamage inflictedSusceptibility to damageFull sib/half sib mating experimentsSACGay et al. 2011Reduced spinesNo correlated responseExperimental evolutionSACCayetano et al. 2011 Carabid beetles (Ohomopterus)Apophysis of the endophallusVaginal appendix (pocket attached to the vaginal apophysis)Cross-species matingsLock and keySota and Kubota 1998; Sasabi et al. 2010 Dung beetle: Onthophagus taurusShape of the parameres in the aedagusSize and location of genital pitsExperimental evolutionFemale choiceSimmons and García-González 2011 Diptera: Drosophila santomea and D. yakubaSclerotized spikes on the aedagusCavities with sclerotized plateletsCross-species matingsSACKamimura 2012 Drosophila melanogaster species complexEpandrial posterior lobes
Oviscapt pouchesComparative among speciesSAC or female choiceYassin and Orgogozo 2013Phallic spikesOviscapt furrowsCercal teeth, phallic hook, and spinesUterine, vulval, and vaginal shields D. mauritiana and D. secheliaPosterior lobe of the genital archWounding of the female abdomenMating with introgressed linesSACMasly and Kamimura 2014 Stalk-eyed flies (Diopsidae)Genital processCommon spermathecal ductComparative among species and morphologicalFemale choiceKotrba et al. 2014 Tse-tse flies: Glossina pallidipesCercal teethFemale-sensing structuresExperimental copulatory functionFemale choiceBriceño and Eberhard 2009a,b Phelebotomine: sand fliesAedagal filaments, aedagal sheathsSpermathecal ducts length, base of the ductComparative among speciesNone specifiedIlango and Lane 2000 Heteroptera: Bed bugs (Cimiciidae)Piercing genitaliaSpermalege (thickened exosqueleton)Comparative among speciesSACCarayon 1966; Morrow and Arnqvist 2003 Plant bugs (Coridromius)Changes in male genital shapeExternal female paragenitaliaComparative among speciesSACTatarnic and Cassis 2010 Waterstriders (Gerris sp.)Grasping appendagesAntigrasping appendagesComparative among speciesSACArnqvist and Rowe 2002 Gerris incognitusGrasping appendagesAntigrasping appendagesComparative among populationsSACPerry and Rowe 2012 Bee assassins (Apiomerus)AedagusBursa copulatrixComparative among speciesNoneForero et al. 2013 Cave insects (Psocodea), NeotroglaMale genital chamberPenis-like gynosomeComparative among speciesFemale competition (role reversal), coevolution SACYoshizawa et al. 2014 Butterflies (Heliconiinae)Thickness of spermatophore wallSigna: Sclerotized structure to break spermatophoresComparative among speciesSACSánchez and Cordero 2014Fish Basking shark: Cetorhinus maximusClasper clawThick vaginal padsMorphological observationNoneMatthews 1950 GambusiaGonopodial tipsGenital papillae within openingsComparative among speciesStrong character displacementLangerhans 2011 Poecilia reticulataGonopodium tip shapeFemale gonopore shapeComparative among populationsSACEvans et al. 2011Reptiles AnolesHemipene shapeVagina shapeShape correspondence, two speciesSexual selectionKöhler et al. 2012 Several speciesHemipene shapeVagina shapeShape correspondenceLock and key, female choice, and SACPope 1941; Böhme and Ziegler 2009; King et al. 2009 Asiatic pit vipersSpininess in hemipenesThickness of vagina wallTwo-species comparisonNonePope 1941 Garter snake: Thamnophis sirtalisBasal hempene spineVaginal muscular controlExperimental manipulationSACFriesen et al. 2014Birds WaterfowlPenis lengthVaginal elaborationComparative among speciesSACBrennan et al. 2007 TinamousPenis length/presenceVaginal elaborationComparative among speciesFemale choice/natural selectionPLR Brennan, K Zyscowski, and RO Prum, unpubl.Mammals MarsupialsBifid penisTwo lateral vaginaeShape correspondenceNoneRenfree 1987 EquidnaBifid penis with four rosettesSingle vagina splits into two uteriShape correspondenceNoneAugee et al. 2006; Johnston et al. 2007 Insectivores: Short-tailed shrew: Blarina brevicaudaS-shaped curve of the erect penisCoincident curve in the vaginaShape correspondenceNoneBedford et al. 2004 Common tenrec: Tenrec caudatusFiliform penis (up to 70% of the male’s body length)Internal circular folds in the vaginaLength correspondenceNoneBedford et al. 2004 Rodents: Cape dune mole: Bathyergus suillusPenis and baculum lengthVaginal lengthAllometric relationships within speciesNoneKinahan et al. 2007 Australian hopping mice (Notomys)Spiny penisDerived distal region in the vaginaMorphological observation and two-species comparisonCopulatory lockBreed et al. 2013 Pig: Sus domesticusFiliform penis endCervical ridgesArtificial inseminationFemale choiceBonet et al. 2013 Primates: Macaca arctoidesLong and filamentous glansVestibular colliculus (fleshy fold) that partially obstructs the entrance to the vaginaShape correspondence and comparison with close relativesNoneFooden 1967Open in a separate windowThe likely mechanism is that suggested by the authors, and it includes sexually antagonistic coevolution (SAC), natural selection, sexual selection, female choice, or none specified. The evidence provided by the studies can be comparative among species or among populations, experimental evolution, cross-species matings, full-sibling (sib)/half-sib matings, shape, and length correspondence. Shape correspondence is often taken as evidence of coevolution, although it is not as conclusive as other approaches.Male genitalia are among the most variable structures in nature (Eberhard 1985). In contrast, female genitalia have typically been found not to be as interspecifically variable as male genitalia in several studies that specifically examined and described them (Eberhard 1985, 2010a,b). Female genitalia are not studied as often as male genitalia, perhaps because of a male-biased view of evolutionary processes by researchers (Ah-King et al. 2014). However, studying female genitalia is undeniably challenging. Male genitalia are generally kept inside of the body cavity, but are everted before, or during copulation, so their functional morphology can be more easily studied than the internal genitalia of females. Female genitalia also tend to be softer than male genitalia and thus their morphology may be more difficult to describe, and can more easily be distorted on dissection and preservation. Female adaptations to sense or oppose features of male genitalia can be subtle, requiring careful study. Female genital tracts are under multiple sources of selection: not just mating, but also storing sperm, egg laying, birthing, and often interfacing with the terminal portion of the digestive tract. Therefore, selection balancing multiple functions may further constrain morphological evolution in female genitalia. However, even small morphological changes in female genitalia, for example, increases in vaginal muscle, may change a female’s ability to choose or reject a male during mating, or to manage the costs of mating. Thus, the functional consequences to male and female genital morphology are hard to predict unless one knows how genitalia function during intromission. Despite these challenges, recent studies have examined variation of female genitalia and evidence is accumulating that features of female genitalia are variable enough to support coevolutionary processes (Polihronakis 2006; Puniamoorthy et al. 2010; Siegel et al. 2011; Showalter et al. 2013; and see additional references in Ah-King et al. 2014).In this article, we will discuss different hypotheses of genital evolution that predict coevolution; however, this is not a review of that entire subject (but see Eberhard et al. 2010b; Simmons 2013). Rather, we discuss the various mechanisms of genital coevolution differentiating the potentially independent or overlapping roles of natural selection, female choice, and male–male competition (Fig. 1). This classification allows us to distinguish specifically those mechanisms of genital coevolution that involve sexual conflict (i.e., when the evolutionary interests of individuals of different sexes, particularly over mating, are different). We then highlight examples in different taxa organisms with particular emphasis on those that provide evidence of sexual conflict.Open in a separate windowFigure 1.Graphical classification of mechanisms of genital evolution and coevolution. Three circles depict the independent and co-occurring actions of natural selection, female choice, and male–male competition. Different specific versions of genital coevolution can occur depending on which of the three broader evolutionary mechanisms are occurring. Sexual conflict (hatched lines) occurs through the simultaneous action of male–male competition and female choice, or male–male competition and natural selection. SAC, sexually antagonistic coevolution. See text for explanation.