Investigating the Effect of Familiarity on Kin Recognition of Three‐Spined Stickleback (Gasterosteus aculeatus)

The ability to discriminate between related and unrelated individuals has been demonstrated in many species. The mechanisms behind this ability might be manifold and depend on the ecological context in which the species lives. In brood‐caring species, both familiarity and phenotype matching are known to be used in kin recognition. However, results of studies disentangling these two phenomena have proved contradictory. We aimed to broaden our knowledge about the mechanisms of kin recognition using shoaling preferences of three‐spined stickleback (Gasterosteus aculeatus) as a model behavior. In our first experiment, focal fish had the choice to shoal either with kin or unfamiliar non‐kin. In half of the trials, kin groups were composed of familiar individuals, while they were unfamiliar in the other half. Focal fish significantly preferred kin as shoaling partner, a result which was not reinforced by familiarity. In our second experiment, focal fish were given the choice between a shoal of familiar kin and a shoal of unfamiliar kin. Here, focal fish did not show any significant preference. These results indicate that familiarity does not impact stickleback's ability to recognize kin. Furthermore, they show that familiarity does not overrule recognition based on phenotype matching or innate recognition, underlining the importance of these mechanisms. Finally, our results lead to the assumption that individual recognition might play a minor role also in non‐kin‐based preferences for familiars.     

Geographical distribution of genotypic and phenotypic markers among Bacillus anthracis isolates and related species by historical movement and horizontal transfer

The geographical distribution of Bacillus anthracis strains and isolates bearing some of the same genetic markers as the Amerithrax Ames isolate was examined and evaluated. At least one mechanism for the horizontal movement of genetic markers was shown amongst isolates and closely related species and the effect of such mixing was demonstrated on phenotype. The results provided potential mechanisms by which attempts to attribute isolates of Bacillus anthracis to certain geographical and isolate sources may be disrupted.     

Whole genome comparison of six Crocosphaera watsonii strains with differing phenotypes

Crocosphaera watsonii, a unicellular nitrogen‐fixing cyanobacterium found in oligotrophic oceans, is important in marine carbon and nitrogen cycles. Isolates of C. watsonii can be separated into at least two phenotypes with environmentally important differences, indicating possibly distinct ecological roles and niches. To better understand the evolutionary history and variation in metabolic capabilities among strains and phenotypes, this study compared the genomes of six C. watsonii strains, three from each phenotypic group, which had been isolated over several decades from multiple ocean basins. While a substantial portion of each genome was nearly identical to sequences in the other strains, a few regions were identified as specific to each strain and phenotype, some of which help explain observed phenotypic features. Overall, the small‐cell type strains had smaller genomes and a relative loss of genetic capabilities, while the large‐cell type strains were characterized by larger genomes, some genetic redundancy, and potentially increased adaptations to iron and phosphorus limitation. As such, strains with shared phenotypes were evolutionarily more closely related than those with the opposite phenotype, regardless of isolation location or date. Unexpectedly, the genome of the type‐strain for the species, C. watsonii WH8501, was quite unusual even among strains with a shared phenotype, indicating it may not be an ideal representative of the species. The genome sequences and analyses reported in this study will be important for future investigations of the proposed differences in adaptation of the two phenotypes to nutrient limitation, and to identify phenotype‐specific distributions in natural Crocosphaera populations.     

EVOLUTION OF IDENTITY SIGNALS: FREQUENCY‐DEPENDENT BENEFITS OF DISTINCTIVE PHENOTYPES USED FOR INDIVIDUAL RECOGNITION

Identifying broad‐scale evolutionary processes that maintain phenotypic polymorphisms has been a major goal of modern evolutionary biology. There are numerous mechanisms, such as negative frequency‐dependent selection, that may maintain polymorphisms, although it is unknown which mechanisms are prominent in nature. Traits used for individual recognition are strikingly variable and have evolved independently in numerous lineages, providing an excellent model to investigate which factors maintain ecologically relevant phenotypic polymorphisms. Theoretical models suggest that individuals may benefit by advertising their identities with distinctive, recognizable phenotypes. Here, we test the benefits of advertising one's identity with a distinctive phenotype. We manipulated the appearance of Polistes fuscatus paper wasp groups so that three individuals had the same appearance and one individual had a unique, easily recognizable appearance. We found that individuals with distinctive appearances received less aggression than individuals with nondistinctive appearances. Therefore, individuals benefit by advertising their identity with a unique phenotype. Our results provide a potential mechanism through which negative frequency‐dependent selection may maintain the polymorphic identity signals in P. fuscatus. Given that recognition is important for many social interactions, selection for distinctive identity signals may be an underappreciated and widespread mechanism underlying the evolution of phenotypic polymorphisms in social taxa.     

Kin discrimination in sticklebacks is mediated by social learning rather than innate recognition

Theory predicts several advantages for animals to recognize kin. These include inbreeding avoidance and an increase in inclusive fitness. In shoaling species, kin recognition may lead to an increased amount of altruism among shoal members. Adult, non‐reproductive three‐spined sticklebacks, Gasterosteus aculeatus, prefer to shoal with kin. This preference was shown for familiar as well as for unfamiliar individuals. However, whether it is based on learned cues of familiar individuals or on innate mechanisms like self‐referent phenotype matching or ‘true’ kin recognition through recognition alleles remains unknown. In our experiments, juvenile fish were given the choice between shoals that differed in relatedness and familiarity. The number of testfish who joined each group indicated that sticklebacks prefer to shoal with familiar kin when the alternative shoal was composed of unfamiliar non‐kin. When one shoal consisted of familiar kin while the second consisted of familiar non‐kin testfish did not show any preference. Kin recognition in sticklebacks is thus most likely mediated by social learning.     

Origin and differentiation of Aegilops triuncialis L. as determined by esterase isozyme analysis

Summary Banding patterns of esterase isozymes in Aegilops triuncialis (2n = 28, genome formula C^uC^uCC) and its putative parental species, Ae. umbellulata (2n = 14, C^uC^u) and Ae. caudata (2n = 14, CC), were studied by the gel isoelectric focusing method using pH 6–8 carrier ampholite. Zymogram phenotypes of both parents were quite uniform. Seven zymogram phenotypes (designated as phenotypes 1 to 7) were found among the 260 strains of Ae. triuncialis examined. Of these phenotypes, phenotype 1 was identical to the zymogram phenotype produced by the ancestral species, Ae. umbellulata, and bands considered to have been derived from Ae. caudata were absent in this phenotype. Phenotype 3 had all bands of both parents. The other phenotypes differed greatly from phenotype 3. Therefore, phenotype 3 was considered to be most primitive of the 7 types, and the Ae. triuncialis strains which showed phenotype 3 to be the most primitive of the strains examined. If Ae. triuncialis originated as a hybrid between Ae. umbellulata and Ae. caudata, the zymogram phenotype must have been phenotype 3, in which the isozymes of both parental species are present. Whether the phenotypes other than type 3 were due to introgressive hybridization could not be verified, but they were considered in this article to be a consequence of a rearrangement of chromosomes.Contribution from the Laboratory of Genetics, Faculty of Agriculture, Kyoto University No. 432     

Similarities of genome deoxyribonucleic acids ofPseudomonas strains isolated from meat

A total of 29Pseudomonas strains from meat and 14 reference strains of differentPseudomonas species were studied by DNA-DNA hybridization. Of the field strains, 15 were phenotypically similar toP. fragi; the others represented a new group described by Molin and Ternström [4], phenotypically related toP. fragi and the fluorescent pseudomonads; 12 strains of this phenotype formed one major DNA-relatedness group; the type strain ofP. fragi together with nine field strains formed another group. The remaining eight meat isolates could not be assigned to either of the two groups. The intergroup relatedness and the relatedness of both groups to the fluorescent pseudomonads was about 50%. Hybridization data indicate that the phenotype of Molin and Ternström deserves species rank and that this tentative species andP. fragi belong to the group of fluorescent pseudomonads.     

Origin and evolution of the waxy phenotype in Amaranthus hypochondriacus: evidence from the genetic diversity in the Waxy locus

The existence of polymorphism in the Waxy locus in a large gene pool of 53 strains with various waxy phenotypes from samples of Amaranthus hypochondriacus collected from different regions was investigated in an origin-and-evolution study. First, we screened all strains for a mutation point (G–A polymorphism in exon 6) by using PCR–RFLP and/or direct sequence analysis. The results showed that the nonsense mutation in the coding region (exon 6) of the Waxy gene was responsible for the change in perisperm starch, leading to a waxy phenotype in all strains. Second, phylogenetic analysis, which was based on the Waxy variation, indicated diverse waxy types occurring separately and independently in certain domesticated regions in Mexico. Finally, we designated nine molecular types by comparing obvious structural variations in the coding region of the Waxy gene. Among the molecular types, A. hypochondriacus contained Type III in three subtypes with the waxy phenotype, with evolutionary routes that could originate from Type II in accordance with G–A polymorphism. In addition, these types had the same mutation points by which the Waxy gene was converted into the waxy phenotype. Therefore, the present results showed that the nonsense mutation is a unique event in the evolution of waxy phenotypes in this crop. This study will provide useful information for understanding the evolutionary process of the waxy phenotype.     

Sex-limited genetic variation in a mouse salivary protein

This report describes a gene which influences the electrophoretic mobility of a protein in the salivas of adult mice. Three categories of phenotype have been observed: the two single-banded types, F (Fast) and S (Slow), and the two-banded type, SF (Slow-Fast), with the two bands represented in varying proportions. All females, regardless of age or strain, and all males before puberty show only the F phenotype. Males of the BALB/c and C57BL/6J strains show the F phenotype throughout puberty and adult life, whereas males of the C3H/St and C57BL/KsJ strains show the SF phenotype in puberty and the S phenotype in adult life. We have designated this variation the sex-limited saliva pattern (Ssp). The results from genetic crosses indicate that the variation among the strains is determined by an autosomal locus, Ssp, with two alleles, Ssp ^S andSsp ^F ,where Ssp ^S is dominant to Ssp ^F .Testosterone treatment can accelerate the acquisition of the S type in males of the strains C3H/St and C57BL/KsJ and also induces that phenotype in C3H/St females and C57BL/6J males. Thus it appears that the observed strain-specific differences reflect a genetic variation in androgen levels and/or androgen sensitivity rather than variation in a structural gene.This study was supported in part by PHS Research Grant 5 RO1 AM21177 and by the Indiana University Human Genetics Center (PHS PO1 GM21054). The preliminary work was done during a 1-month visit by RCK to the Institute of Ecology and Genetics which was supported by the University of Aarhus. This is publication No. 80-18 from the Department of Medical Genetics. RCK was supported by PHS Career Development Award 1 KO4 AM00284. SRD was supported by PHS General Medical Training Grant T32 GM07468.     

Adherent-invasive Escherichia coli, strain LF82 disrupts apical junctional complexes in polarized epithelia

Background  

Although bacteria are implicated in the pathogenesis of chronic inflammatory bowel diseases (IBD), mechanisms of intestinal injury and immune activation remain unclear. Identification of adherent-invasive Escherichia coli (AIEC) strains in IBD patients offers an opportunity to characterize the pathogenesis of microbial-induced intestinal inflammation in IBD. Previous studies have focused on the invasive phenotype of AIEC and the ability to replicate and survive in phagocytes. However, the precise mechanisms by which these newly identified microbes penetrate the epithelial lining remain to be clarified. Therefore, the aim of this study was to delineate the effects of AIEC, strain LF82 (serotype O83:H1) on model polarized epithelial monolayers as a contributor to intestinal injury in IBD.     

Effect of chromosome arrangements on mate recognition system leading to behavioral isolation in <Emphasis Type="Italic">Drosophila ananassae</Emphasis>

The mechanisms of speciation that appear in the early stages of reproductive isolation has been of recent interest to evolutionary biologists. Experiments were conducted to study behavioral isolation between karyotypically different homozygous strains derived from natural populations of Drosophila ananassae. Three mass cultures stocks established from flies collected from natural populations were employed and homozygous stocks (ST/ST and AL/AL) were made through selection for homozygosity. By employing male-choice technique, mating success was scored by direct observation in the Elens–Wattiaux mating chamber. There is preference for homogamic matings in all the three populations and the differences between homogamic and heterogamic matings are statistically significant in two populations (Lucknow and Varanasi). These findings provide evidence that there is incipient sexual isolation between karyotypically different strains of D. ananassae derived from natural populations which shows that chromosome arrangements may affect the mate recognition system in D. ananassae.     

Genetic analysis of the φC31 -specific phage growth limitation (Pgl) system of Streptomyces coelicolor A3(2)

The phage growth limitation (Pgl) system of Streptomyces coelicolor A3(2) was shown to be specific to φC31 homo-immune phages, and to be absent from the closely related strain Streptomyces Iividans. A 16 kb fragment of S. coelicolor A3(2) DNA was isolated which complemented the Pgl^? phenotype of J1501, a pgl mutant derivative of the Pgl^tsS. coelicolor strain M130. The cloned DNA complemented only half of the available pgl mutants, which therefore represented at least two groups, designated Pgl class A and class B strains. It follows that more than one kind of high-frequency genetic event can lead to the Pgl^? phenotype. Crosses between class A and class B strains yielded high frequencies of Pgl⁺ recombinants. Crosses between strains of the same class gave no Pgl⁺ recombinants. The cloned DNA was altered by deletion or apparent point mutation upon passage through the two class B strains tested, such that it was no longer capable of complementing class A strains. This accumulation of mutations might suggest that the expression of the cloned DNA is toxic to at least some class B strains. The nature of the genetic instability associated with the Pgl system was not detectable by Southern blot analysis.     

Polymorphism of esterase 11 in Mus musculus,a further esterase locus on chromosome 8

A further esterase, esterase 11, which exhibits a polymorphism detectable by electrophoresis, has been observed in the house mouse, Mus musculus. In 15 inbred strains and two outbred strains, the ES-11A phenotype has been found, composed of two bands of enzyme activity of greater anodal electrophoretic mobility than the two bands of the ES-11B phenotype found in one inbred strain, one wild stock, and 101 wild mice. In F₁ hybrids (IS/Cam×C57 BL/Gr), the phenotype shown corresponds to a mixture of the two parental phenotypes. In backcrosses, ES-11 segregates as an autosomal gene, designated Es-11, closely linked to Es-2 and Es-5 on chromosome 8.This work was supported by the Medical Research Council.     

L3T4 but not LFA-1 participates in antigen presentation by Ak-positive L-Cell transformants

Genomic DNA was isolated from 29 t strains and 4 congenic lines of mice, digested with restriction endonucleases, and hybridized with a probe representing the complement component 4 (C4) gene. All but one of the enzymes revealed restriction fragment length polymorphism in this sample of C4-related genes. Double digestion analysis suggested the presence of three C4 gene copies in some of the t chromosomes and two copies in others. The enzymes distinguished 16 different haplotypes among the 33 strains tested. Based on their restriction fragment length patterns, the t strains could be divided into four groups with strains in each group more closely related to each other with respect to their C4-region genes than strains belonging to different groups. At least three of these four groups represent different branches of the evolutionary tree constructed for the t chromosomes. The C4-related genes of the chromosomes are in strong linkage disequilibrium with the class II genes of the H-2 complex. Typing for the Ss and Slp allotypes of C4 has revealed the presence of the Ss¹ phenotype in two t strains and of the Slp^a phenotype in one strain.     

Kin Recognition in the largely Solitary Bee,Manuelia postica (Apidae: Xylocopinae)

The recognition of conspecifics is a central issue to social behaviour. In eusocial hymenopterans, kin recognition has been clearly demonstrated. Manuelia postica is a largely solitary bee species in which larvae develop inside individual cells within a nest and remain isolated from conspecifics until the destruction of partitions by adults. Nestmate recognition in M. postica has been previously demonstrated under experimental conditions. Isolation between individuals during development and nestmate recognition ability in adult females make M. postica an ideal species for testing the occurrence of kin recognition capacity in females. Kin recognition was demonstrated through cross‐fostering field experiments involving the single transfer of recently enclosed larvae, and subsequent laboratory recognition bioassays with emerging females. Results suggest kin recognition occurs through self‐referent phenotype matching. Given the basal position of Manuelia in the phylogeny of the Apidae, kin recognition may represent an ancestral recognition mechanism in Apidae species phylogenetically more derived than M. postica.     

Repair of DNA double-strand breaks in Escherichia coli K12 requires a functional recN product

Summary Mutation of the recN gene of Escherichia coli in a recBC sbcB genetic background blocks conjugational recombination and confers increased sensitivity to UV light and mitomycin C. The basis for this phenotype was investigated by monitoring the properties associated with recN mutations in otherwise wild-type strains. It was established that recN single mutants are almost fully resistant to UV irradiation, and that there is no detectable defect in repair of UV lesions by excision, error-prone, or recombinational mechanisms. However, recN mutations confer sensitivity to mitomycin C and ionizing radiation both in wild-type and recB sbcB strains. The sensitivity to ionizing radiation is correlated with a deficiency in the capacity to repair DNA double-strand breaks by a UV inducible mechanism. Recombinant phages that complement the recombination and repair defects of recN recBC sbcB mutants have been identified, and the recN gene has been cloned from these phages into a low copy-number plasmid.     

Geographical distribution and genetic analysis of phenol color reaction in foxtail millet,Setaria italica (L.) P. Beauv.

Summary Phenol color reaction was examined in a total of 376 strains of foxtail millet, Setaria italica (L.) P. Beauv., collected from different areas throughout Eurasia. Positive and negative phenotypes, and no intermediate type could be recognized by the phenol color reaction. Of 376 strains examined, 50 were positive, 319 were negative, five were mixtures of both phenotypes, and the coloration in two strains with blackish lemmata and paleae could not be distinguished. The strains that showed the positive phenotype of phenol color reaction were found in rather limited regions, while those with the negative phenotype occurred in almost all the regions. The positive phenotype occurred more frequently in the lower latitudinal regions of Asia. Genetic analysis of the F₁ and F₂ generations between the two phenotypes showed that the phenol color reaction is controlled by a single gene, and that the positive phenotype is dominant.Contribution No. 28 from the Plant Germ-plasm Institute, Faculty of Agriculture, Kyoto University, Kyoto (Japan)     

酒鬼酒酿造环境异常球菌属菌株的生物学特征及系统发育分析

研究对分离自馥郁香型白酒酒鬼酒制曲和发酵车间空气的8株异常球菌属(Deinococcus)菌株的特征及系统发育分析进行研究。采用添加体积分数10%酒鬼酒混合浸汁的营养琼脂培养基分离,挑选并纯化与异常球菌属菌株表型相似的菌株,考察其相关生理生化特征,并进行基于16S rRNA基因序列的系统发育分析。通过表型特点筛选,得到23株异常球菌属疑似菌株。系统发育分析表明,23株菌株中有8株属于异常球菌属,归属于该属的4个种(D.radiotolerans、D.daejeonensis、D.ficus和D.yunweiensis)。形态观察和生理生化实验表明,这些异常球菌属菌株在内生孢子、革兰染色、过氧化氢酶实验、生长温度范围、生长pH范围、多聚物水解等特征方面,与它们系统发育关系最为密切的典型菌株之间存在不同程度的差异。