Autopodial skeleton evolution in side-necked turtles (Pleurodira)

Carpal and tarsal anatomy was documented based on the observation of dry skeletons of adult specimens representing 25 species in 15 genera and on data taken from the literature. In addition, histological sections and cleared and double‐stained autopodia of recently hatched and juvenile specimens representing seven chelid and pelomedusoid species were studied. There is much more morphological diversity in the manus than in the pes. Variation in autopodial skeletons includes: the astragalus and calcaneum are either separated or fused; fusion of distal carpals 3–4−5 or just 4–5; number of centralia in the carpus; and presence/absence of a pisiform and of an accessory radial element. The widespread and probably basal phalangeal formula for Pleurodira is 2.3.3.3.3. Deviations are Pelomedusa subrufa, exhibiting a reduction to 2.2.2.2.2, Pelusios spp. with one phalanx less in digit I and for one species in digit V as well, and Acanthochelys pallidipectoris with an additional phalanx in the fourth finger. Six discrete characters itemizing some of the morphological variation observed were plotted on a composite pleurodire phylogeny, revealing not only homoplastic patterns but also the utility of some characters in supporting the monophyly of several clades. The pisiform is the last carpal element to ossify in Chelus fimbriatus. We hypothesize that the so‐called fifth hooked metatarsal represents the fusion of distal tarsal 5 with metatarsal V. The accessory radial element that was occasionally present in the turtles examined may represent an atavism of the otherwise lost radiale of turtles.     

A phylogeny for side-necked turtles (Chelonia: Pleurodira) based on mitochondrial and nuclear gene sequence variation

Aspects of the phylogeny of pleurodiran turtles are contentious, particularly within the Chelidae. Morphological analyses group the long-necked Australasian Chelodina and the long-necked South American Chelus and Hydromedusa into a single clade, suggesting a common derived origin of the long neck and associated habits that predated the separation of Australia from South America. In contrast, published analyses of 12SrRNA and cytochrome b sequences suggest that the long-necked Chelodina are more closely related to the short-necked Australasian genera than to either Chelus or Hydromedusa. This paper adds partial sequences of 16S rRNA and CO1 mitochondrial genes and partial sequences of the nuclear oncogene c-mos to test a range of previous hypotheses on the phylogenetic relationships among chelid turtles. In total, 1382 nucleotides were available for each of 25 taxa after elimination of ambiguously aligned regions. These taxa included representatives of all the genera of the turtle families Chelidae and Pelomedusidae, the three sub-genera of Phrynops, and recognized sub-generic groups of Elseya and Chelodina. Of the four genes examined, 12S rRNA was the most informative, followed by c-mos with 16S rRNA and CO1 the least informative. The molecular data support the currently accepted arrangement for pelomedusid genera, that is, a sister relationship between the African Pelusios and Pelomedusa and a clade comprising the South American Peltoceplhalus and Podocnemis with the Madagascan Erymnochelys. However, there is also support for Erymnochelys and Podocnemis as sister taxa to the exclusion of Peltocephalus (bootstrap values of 69–80%) which is at odds with the most commonly accepted arrangement. The South American chelids are monophyletic (76–82%). This clade includes the long-necked Chelus and Hydromedusa, but excludes the Australasian long-necked Chelodina. Furthermore, the South American long-necked chelids are not themselves monophyletic, with 98–100% bootstrap values for the node supporting Chelus and the remaining South American chelids to the exclusion of Hydromedusa. Hence, the hypothesis of a monophyletic grouping of the long-necked genera of South America and Australasia is not supported by the molecular data. Although reciprocal monophyly of the South American and Australasian chelid faunas was the most likely and the most parsimonious arrangement in all but one analysis, bootstrap support for the monophyly of the Australasian chelids was low (52–66%). The South American chelids, Chelodina and the short-necked Australasian chelids form an unresolved trichotomy. The genera Phrynops and Elseya are paraphyletic, leading to a recommendation to elevate the three sub-genera of Phrynops to generic status and support for previous suggestions to erect a new genus for Elseya latistermum and close relatives. A revised classification of the extant Pleurodira is presented, consistent with the phylogenetic relationships that emerge from this study.     

Proopiomelanocortin (POMC) and testing the phylogenetic position of turtles (Testudines)

Morphological and molecular studies have inferred multiple hypotheses for the phylogenetic relationships of Testudines. The hypothesis that Testudines are the only extant anapsid amniotes and the sister taxon of diapsid amniotes is corroborated by morphological studies, while the hypothesis that Testudines are diapsid amniotes is corroborated by more recent molecular and morphological studies. In this study, the placement of Testudines is tested using the full length cDNA sequence of the polypeptide hormone precursor proopiomelanocortin (POMC). Because only extant taxa have been used, the hypotheses being tested are limited to the following (1) Testudines as the sister taxon of Archosauria, (2) Testudines included in Archosauria and the sister taxon of Crocodilia, (3) Testudines as the sister taxon of Lepidosauria, (4) Testudines as the sister taxon of Sauria, and (5) Testudines as the sister taxon of a monophyletic Mammalia–Sauria clade. Neither Maximum likelihood, Bayesian, or maximum parsimony analyses are able to falsify the hypothesis of (Archosauria (Lepidosauria, Testudines)) and as such is the preferred inference from the POMC data.     

DNA barcoding of Brazilian sea turtles (Testudines)

Five out of the seven recognized species of sea turtles (Testudines) occur on the Brazilian coast. The Barcode Initiative is an effort to undertake a molecular inventory of Earth biodiversity. Cytochrome Oxidase c subunit I (COI) molecular tags for sea turtle species have not yet been described. In this study, COI sequences for the five species of sea turtles that occur in Brazil were generated. These presented widely divergent haplotypes. All observed values were on the same range as those already described for other animal groups: the overall mean distance was 8.2%, the mean distance between families (Dermochelyidae and Cheloniidae) 11.7%, the mean intraspecific divergence 0.34%, and the mean distance within Cheloniidae 6.4%, this being 19-fold higher than the mean divergence observed within species. We obtained species-specific COI barcode tags that can be used for identifying each of the marine turtle species studied.     

Diversity of North American map and sawback turtles (Testudines: Emydidae: Graptemys)

Map turtles of the genus Graptemys are native to North America, where a high degree of drainage endemism is believed to have shaped current diversity. With 14 species and one additional subspecies, Graptemys represents the most diverse genus in the family Emydidae. While some Graptemys species are characterized by pronounced morphological differences, previous phylogenetic analyses have failed yet to confirm significant levels of genetic divergence for many taxa. As a consequence, it has been debated whether Graptemys is taxonomically inflated or whether the low genetic divergence observed reflects recent radiations or ancient hybridization. In this study, we analysed three mtDNA blocks (3228 bp) as well as 12 nuclear loci (7844 bp) of 89 specimens covering all species and subspecies of Graptemys. Our analyses of the concatenated mtDNA sequences reveal that the widespread G. geographica constitutes the sister taxon of all other Graptemys species. These correspond to two clades, one comprised of all broad‐headed Graptemys species and another clade containing the narrow‐headed species. Most species of the broad‐headed clade are reciprocally monophyletic, except for G. gibbonsi and G. pearlensis, which are not differentiated. By contrast, in the narrow‐headed clade, many currently recognized species are not monophyletic and divergence is significantly less pronounced. Haplotype networks of phased nuclear loci show low genetic divergence among taxa and many shared haplotypes. Principal component analyses using coded phased nuclear DNA sequences revealed eight distinct clusters within Graptemys that partially conflict with the terminal mtDNA clades. This might be explained by male‐mediated gene flow across drainage basins and female philopatry within drainage basins. Our results support that Graptemys is taxonomically oversplit and needs to be revised.     

Molecular phylogeny of Central and South American slider turtles: implications for biogeography and systematics (Testudines: Emydidae: Trachemys)

We analyse phylogeny, systematics and biogeography of slider turtles (Trachemys spp.) using sequence data of four mitochondrial genes (3242 bp) and five nuclear loci (3396 bp) of most South American and southern Central American taxa and representatives of northern Central American, West Indian and North American slider species (16 species and subspecies) and allied North American species (genera Chrysemys, Deirochelys, Graptemys, Malaclemys, Pseudemys). By applying maximum likelihood, relaxed molecular clock and ancestral range analyses, we provide evidence for two successive colonizations of South America by slider turtles. In addition, we show that the current species delineation of Central and South American slider turtles is incorrect. Our data suggest that Trachemys grayi is a distinct polytypic species that embraces, besides the nominotypical subspecies, T. g. emolli and T. g. panamensis. Trachemys ornata is also polytypic with the subspecies T. o. ornata, T. o. callirostris, T. o. cataspila, T. o. chichiriviche and T. o. venusta. Moreover, T. adiutrix should be regarded as a subspecies of T. dorbigni. All studied Trachemys species are inferred to have originated in the Late Miocene to Early Pliocene. The ancestor of the two subspecies of T. dorbigni colonized South America most probably prior to the establishment of the land bridge connecting Central and South America, whereas the two South American subspecies of T. ornata represent a younger independent immigration wave from Central America.     

Description of Auriculotrema lechneri n. gen., n. sp. (Digenea: Choanocotylidae), a parasite of freshwater turtles (Testudines: Pleurodira: Chelidae) from Queensland,Australia

Auriculotrema lechneri n. gen., n. sp. is described from the small intestine of Emydura krefftii and Elseya latisternum from northern Queensland, Australia. The new species strongly resembles species of Choanocotyle in body shape, ventral incision of the oral sucker, structure of the cirrus sac, and location of the genital pore. The distinctive taxonomic feature is the presence of 2 winglike projections extending beyond the lateral margins of the oral sucker, in contrast to the extremely large, expanded oral sucker diagnostic of Choanocotyle spp. Auriculotrema n. gen. is the second genus included in the formerly monotypic Choanocotylidae Jue Sue and Platt, 1998.     

Kinematics and functional morphology of aquatic feeding in Australian snake-necked turtles (Pleurodira; Chelodina)

Head kinematics during aquatic feeding of the Australian long-necked turtle (Chelodina) were studied by means of high speed video recordings. Buccal expansion was assessed by calculation of elliptical cross-sectional surfaces. Further, displacements of head, carapace, and prey in the earth bound frame, of the prey relative to the center of the gape, and of the head relative to the carapace were determined. Rates of change (velocities) of all these variables were calculated. These data are combined with information on the osteology and myology of the head. The robust development of the large hyobranchial apparatus, the massive intercornuatus muscle, and the presence of the branchiosquamosus muscle were related to aquatic feeding skills. Head kinematics are variable in amplitude and relative timing, but proceed always in a rostrocaudal sequence. According to their effect on the prey, two components are distinguished in the process of expansion. The first compensates for head/body movements (compensatory suction). The second causes distinct acceleration of water and prey (inertial suction). The latter component is mainly driven by the abduction of the second branchial arch. In spite of largely different structural solutions, optimal feeding conditions as deduced for suction in feeding fishes are also employed by Chelodina. This further promotes the assumption that hydrodynamics constrain evolutive solutions for aquatic feeding. J. Morphol. 233:113–125, 1997. © 1997 Wiley-Liss, Inc.     

Phylogenetic implications of karyotypic variation in the Batagurinae (Testudines: Emydidae)

The present study examined karyotypes of 16 genera and, along with previous reports, chromosomal data are now available for 18 of the 23 recognized batagurine genera. There are no karyotypic data available for the members of McDowell's (1964) Hardella complex. The Batagur, Heosemys and Geoemyda complexes retain the hypothesized primitive karyotype for the subfamily (2n=52). All the genera in these three complexes have been examined except Batagur and Annamemys. The Orlitia complex is karyotypically distinct with 2n=50 and the NOR located terminally on a large microchromosome. The genus Malayemys inclusion in the Batagur complex is not supported. Malayemys is characterized by a 2n=50 karyotype, with the NOR located interstitially on a large microchromosome. The Malayemys complex is erected to contain this genus at a point intermediate between the Orlitia complex and the subfamily Emydinae. Malayemys and the emydines are karyotypically indistinguishable. The Neotropical genus Rhinoclemmys (Geoemyda complex) differs only slightly from the primitive batagurine karyotype in the position of the NOR. The species R. funerea and R. punctularia further differ in possessing one less metacentric macrochomosome. An interesting situation involves two subspecies of R. punctularia. The nominate subspecies is characterized by a 2n=56 karyotype, while R. p. melanosterna reportedly has a 2n=52 karyotype. Such a difference is interpreted as indicative of genetic differentiation between the two forms of a magnitude inconsistent with considering them as conspecific. Taken together with zoogeographic considerations, the karyotypic difference between the forms R. p. punctularia and R. p. melanosterna seem sufficient to warrant species distinction for R. melanosterna as previously suggested by Pritchard (1979b).     

Electrophoretic delineation of species boundaries within the short-necked freshwater turtles of Australia (Testudines: Ghelidae)

A total of 222 specimens from 55 populations of short-necked chelid turtle was collected from drainages in Australia and Papua New Guinea. Two populations were initially considered to belong to different diagnosable taxa if all individuals in one population could be distinguished from all individuals in the other by fixed allozyme differences. When two populations or diagnosable taxa shared allozymes at all presumptive loci, their profiles were combined into a single diagnosable taxon. Comparisons between populations and emerging diagnosable taxa were repeated until no further changes were possible. The species Elseya dentata comprised five clearly diagnosable taxa, differing by between 4 and 19 fixed allozyme differences. The currently recognized El. latisternum and El. novaeguineae were each a single diagnosable taxon, and there were three diagnosable taxa, including a sibling pair, that could not be assigned to a currendy described Elseya species. In contrast, all forms of Emydura were very closely related, with no two taxa differing by more than three fixed allozyme differences. There were three diagnosable taxa in the north (Em. victoriae, Em. subglobosa and one new form), though support for them was marginal. In the south, Em. macquarii, Em. krefflii and Em. signata formed only a single diagnosable taxon, even sharing rare alleles. If the phylogenetic species concept is adopted, there is support for recognition of 16 species of short-necked turtle in Australia, including Pseudemydura umbrina. Currendy only 10 are described. Our data also provide evidence of reproductive isolation in some cases (sympatric or parapatric), and comparative evidence (sensu Mayr) in others, than the traditional biological species concept applies also to these diagnosable taxa.     

Two new species of Choanocotyle Jue Sue and Platt, 1998 (Digenea: Choanocotylidae) from an Australian freshwater turtle (Testudines: Pleurodira: Chelidae)

Choanocotyle hobbsi n. sp. and Choanocotyle juesuei n. sp. are described from the small intestine of the oblong turtle Chelodina oblonga from the vicinity of Perth, Western Australia. These are the third and fourth species referred to Choanocotyle. Choanocotyle hobbsi is most similar to Choanocotyle nematoides but differs in the size and shape of the oral sucker and the absence of a median loop in the cirrus sac. Choanocotyle juesuei is most similar to Choanocotyle elegans but differs in the size of the oral sucker and other morphometric criteria. Comparative analysis of the sequences of different nuclear ribosomal deoxyribonucleic acid regions of C. nematoides and C. hobbsi has confirmed that they are closely related but distinct species.     

Phylogenetic relationships and divergence dates of softshell turtles (Testudines: Trionychidae) inferred from complete mitochondrial genomes

The softshell turtles (Trionychidae) are one of the most widely distributed reptile groups in the world, and fossils have been found on all continents except Antarctica. The phylogenetic relationships among members of this group have been previously studied; however, disagreements regarding its taxonomy, its phylogeography and divergence times are still poorly understood as well. Here, we present a comprehensive mitogenomic study of softshell turtles. We sequenced the complete mitochondrial genomes of 10 softshell turtles, in addition to the GenBank sequence of Dogania subplana, Lissemys punctata, Trionyx triunguis, which cover all extant genera within Trionychidae except for Cyclanorbis and Cycloderma. These data were combined with other mitogenomes of turtles for phylogenetic analyses. Divergence time calibration and ancestral reconstruction were calculated using BEAST and RASP software, respectively. Our phylogenetic analyses indicate that Trionychidae is the sister taxon of Carettochelyidae, and support the monophyly of Trionychinae and Cyclanorbinae, which is consistent with morphological data and molecular analysis. Our phylogenetic analyses have established a sister taxon relationship between the Asian Rafetus and the Asian Palea + Pelodiscus + Dogania + Nilssonia + Amyda, whereas a previous study grouped the Asian Rafetus with the American Apalone. The results of divergence time estimates and area ancestral reconstruction show that extant Trionychidae originated in Asia at around 108 million years ago (MA), and radiations mainly occurred during two warm periods, namely Late Cretaceous–Early Eocene and Oligocene. By combining the estimated divergence time and the reconstructed ancestral area of softshell turtles, we determined that the dispersal of softshell turtles out of Asia may have taken three routes. Furthermore, the times of dispersal seem to be in agreement with the time of the India–Asia collision and opening of the Bering Strait, which provide evidence for the accuracy of our estimation of divergence time. Overall, the mitogenomes of this group were used to explore the origin and dispersal route of Trionychidae and have provided new insights on the evolution of this group.     

Multiple data sets, high homoplasy, and the phylogeny of softshell turtles (Testudines: Trionychidae)

We present a phylogenetic hypothesis and novel, rank-free classification for all extant species of softshell turtles (Testudines:Trionychidae). Our data set included DNA sequence data from two mitochondrial protein-coding genes and a approximately 1-kb nuclear intron for 23 of 26 recognized species, and 59 previously published morphological characters for a complimentary set of 24 species. The combined data set provided complete taxonomic coverage for this globally distributed clade of turtles, with incomplete data for a few taxa. Although our taxonomic sampling is complete, most of the modern taxa are representatives of old and very divergent lineages. Thus, due to biological realities, our sampling consists of one or a few representatives of several ancient lineages across a relatively deep phylogenetic tree. Our analyses of the combined data set converge on a set of well-supported relationships, which is in accord with many aspects of traditional softshell systematics including the monophyly of the Cyclanorbinae and Trionychinae. However, our results conflict with other aspects of current taxonomy and indicate that most of the currently recognized tribes are not monophyletic. We use this strong estimate of the phylogeny of softshell turtles for two purposes: (1) as the basis for a novel rank-free classification, and (2) to retrospectively examine strategies for analyzing highly homoplasious mtDNA data in deep phylogenetic problems where increased taxon sampling is not an option. Weeded and weighted parsimony, and model-based techniques, generally improved the phylogenetic performance of highly homoplasious mtDNA sequences, but no single strategy completely mitigated the problems of associated with these highly homoplasious data. Many deep nodes in the softshell turtle phylogeny were confidently recovered only after the addition of largely nonhomoplasious data from the nuclear intron.     

Evolution of the relative width of the head and alveolar surfaces in map turtles (Testudines: Emydidae: Graptemys)

Replicate adaptive radiations are dichotomous morphological patterns related to resource use and repeated in a series of isolated habitats. Biologists have long noted a dichotomy in relative head width and alveolar width among species of map turtles ( Graptemys ), particularly with regard to adult females, which are much larger dian adult males in all 12 species. I measured plastron length (PL), head width (HW), and alveolar width (AW) of nearly 2300 specimens representing the 12 recognized species, and used allometric regressions to investigate this genus as an example of both sexual dimorphism in trophic morphology and replicate adaptive radiation. Sexual dimorphism was noted in HW after correction for PL, with females having wider heads than males of similar body sizes, but AW as corrected for HW was not dimorphic, thus absolute differences in AW are the simple result of differences in HW. Sexual differences in HW probably relate to the dimorphic niches of Graptemys , as females of three species have been reported to occupy deeper water further from shore than conspecific males. Based on predicted HW at maximum PL in adult females, species were categorized as mega-, meso-, or microcephalic. Differences in relative head width are related to differences in degree of molluscivory, with little molluscivory in microcephalic females, moderate to high molluscivory in mesocephalic females, and high molluscivory in megacephalic females. Distributions of Graptemys species in sympatry and allopatry reveal patterns consistent with structuring of distributions via competitive interactions. Superimposing data on relative HW on a phylogeny of the genus suggests there may have been one or two episodes of character displacement, widi subsequent character assortment, in Graptemys evolution. This conclusion is similar to the current model for the evolution of body size during the radation of Anolis lizards in the northern Lesser Antilles.     

Comparison research and phylogenetic implications of mitochondrial control regions in four soft-shelled turtles of Trionychia (Reptilia, Testudinata)

The mitochondrial control regions (CRs) and flanking sequences of Pelodiscus sinensis, Apalone ferox, Palea steindachneri and Carettochelys insculpta were obtained using Long-PCR with gene-specific primers. The CR lengths of the four species were 1843 bp, 1356 bp, 1725 bp, and 969 bp. The base composition percentages of A+T were 60.5%, 60.7%, 65.7%, 64.7%, respectively. Combined with CR sequences of other three soft-shelled turtles published in GenBank (Pelodiscus sinensis, Korea, AY962573; Dogania subplana, AF366350; Lissemys punctata, EF050073), we compared the CR structures and identified three functional domains (TAS, CD and CSB) in which conserved sequence blocks (TAS, CSB -F, CSB-1, CSB-2 and CSB-3) were also successfully identified according to their sequence similarities to those of other turtles. The variable numbers of tandem repeats (VNTRs 1) with 50–52 bp motif were identified at 5′-end of CR among the five soft-shelled turtles P. sinensis (China), P. sinensis (Korea), A. ferox, P. steindachneri, D. subplana. The copy number of the VNTRs varied from 5 to 15. VNTRs 2 with 2–11 bp motif were identified in the 3′- end of CR among all of the six soft-shelled turtles with variable number of motifs from 4 to 29. Moreover, VNTRs 3 with 6 bp motif were identified between CSB-1 and CSB-2 of CR both in P. sinensis (China) and P. sinensis (Korea), in which the number of motifs varied from 19 to 29. The types and distribution of VNTRs of the six soft-shelled turtles were also discussed. With Alligator mississippiensis as an outgroup, combined with the CR sequences (excluding VNTRs) of other five turtles which were published in GenBank, the molecular phylogenetic trees were constructed using PAUP 4.0b10 and MrBayes ver. 3.0. The results strongly supported the monophyly of Carretochelyidae and Carettochelyidae as sister group to an assemblage of Cryptodira. Our research suggested that the earliest phylogenetic tree splits into three separated basal branches; the Pelomedusidira (Pelomedusa subrufa), the Carettochelyidae (C. insculpta), and an assemblage of Cryptodira and the C. insculpta that might be a representation of distinctive suborder.     

Head capsule characters in the Hymenoptera and their phylogenetic implications

The head capsule of a taxon sample of three outgroup and 86 ingroup taxa is examined for characters of possible phylogenetic significance within Hymenoptera. 21 morphological characters are illustrated and scored, and their character evolution explored by mapping them onto a phylogeny recently produced from a large morphological data set. Many of the characters are informative and display unambiguous changes. Most of the character support demonstrated is supportive at the superfamily or family level. In contrast, only few characters corroborate deeper nodes in the phylogeny of Hymenoptera.     

Two new species of Eimeria (Apicomplexa: Eimeriidae) from Asian geoemydid turtles Kachuga tentoria and Melanochelys trijuga (Testudines: Geoemydidae)

Coprological examination of ten Pink-ringed tent turtles Kachuga tentoria circumdata, recently imported from India, and three Burmese black turtles Melanochelys trijuga edeniana, imported from Myanmar, revealed the presence of two new species of Eimeria. Oocysts of Eimeria kachua n. sp. from K. t. circumdata are broadly oval to subspherical, 15.3 (13-18) x 13.9 (12-16) microm, with polar granule and subspherical oocyst residuum. Sporocyst elongatelly oval to spindle-shaped, 8.7 (7.5-10) x 4.9 (4-6) microm, with a knoblike Stieda body, covered with fine membranous cupola-like structures. Thin walled oocysts of Eimeria patta n. sp. from M. t. edeniana, have an irregular shape, influenced by the position of sporocysts, frequently with lobular irregularities, 12.6 (11-16) x 9.1 (7.5-12) microm. Sporocysts are oval to ellipsoidal, 5.8 (5-7) x 4.2 (3.5-5) microm.     

Chromosome studies of the cultured cells of two species of side-necked turtles (Podocnemis unifilis and P. expansa)

The diploid chromosome number of two species of sidenecked turtles (Podocnemis unifilis and P. expansa) was found to be 28. Under normal culture conditions, half of the chromosomes of P. unifilis consistently show one or two clear secondary constrictions. In P. expansa, the incidence of cells with chromosomes bearing secondary constrictions and the number of such chromosomes per cell are less. Cells of two P. unifilis cell lines maintained a normal diploid karyotype for two years following their initiation. Then one cell line shifted to a hypodiploid mode of 27 and half of the population of the second line became pseudodiploid, the other half remaining diploid. A single six-month-old cell line from P. expansa has maintained a normal diploid mode through 10 passages.Supported in part by grant-CA 08737 from the National Cancer Institute.     

Hemoglobins of reptiles. Expression of alpha-D-genes in the turtles, Chrysemys picta bellii and Phrynops hilarii (Testudines)

The hemoglobins of two turtles (Testudines)--Chrysemys picta bellii (suborder Cryptodira) and Phrynops hilarii (suborder Pleurodira)--were investigated. In both specimens we found two hemoglobin components with two distinct alpha-chains. The alpha-chains of the component HbD of Chrysemys picta bellii and of the component CII of Phyrynops hilarii belong to the alpha D-type, which has so far been reported to occur only in birds. The complete amino-acid sequences of both alpha D-chains are presented. Our further investigations on hemoglobins of other reptiles (Crocodilia, Lacertilia, Serpentes) did not give any evidence for the expression of alpha D-globin genes in the species examined. These findings are discussed with especial reference to the physiology of respiration. It is supposed that alpha D-genes were of certain significance in earlier times. There are findings suggesting that alpha D-genes are embryonic genes with persistent expression in many adult birds and turtles.     

Pollen morphology of the Swertiinae (Gentianaceae): phylogenetic implications

Recent molecular surveys of the Swertiinae (Gentianaceae–Gentianeae) revealed unexpected phylogenetic relationships, including polyphyly of the genera Gentianella , Jaeschkea , Lomatogonium and Swertia . To find new non-molecular characters supporting the phylogeny, we examined the exine variation of 73 species of all major lineages of subtribe Swertiinae using environmental scanning electron miscroscopy supplementing older, mainly light microscopical, studies. In contrast to previous studies, we were able to pick out taxa from phylogenetic key positions with particular focus on Swertia . Many distantly related taxa such as parts of Frasera , Gentianopsis , Halenia , Gentianella , Megacodon and several lineages of Swertia share a striate–reticulate or reticulate exine pattern. This is interpreted as the plesiomorphic character state of Swertiinae. There is also considerable variation of derived patterns; for example, different types of microechinate or almost smooth pollen was repeatedly observed in distantly related groups. Another extreme was the ring-shaped reticulation found in a North American species of Gentianopsis . Unfortunately, major relationships as revealed by molecular analyses were rarely supported because of the abundance of the plesiomorphic type and homoplasy even on low taxonomic levels; for example, within Lomatogonium . Exine variation was particularly useful in characterizing independent lineages of Swertia . For example, according to pollen characters and in agreement with other data, the Asian Swertia cuneata is a sister group of a strongly diversified African lineage and Swertia yunnanensis , which is rather aberrant in flower morphology, seems close to parts of Lomatogonium .  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 157 , 323–341.