Review of the genus Chalcolepidius Eschscholtz, 1829 (Coleoptera, Elateridae, Agrypninae)

The genus Chalcolepidius is revised. Type specimens of 65 nominal species, except C. costatus Pjatakowa, 1941, C. fleutiauxi Pjatakowa, 1941 and C. viriditarsus Schwarz, 1906, are examined. Eighty five species are studied, of which 34 are synonymyzed and 12 new species described; three species, C. alicii Pjatakowa, 1941, C. haroldi Candèze, 1878 and C. unicus Fleutiaux, 1910, formely included in this genus, are not congeneric and are removed; C. validus Candèze, 1857 is revalidated. The genus is now formed by 63 species. Redescriptions, illustrations and a key for the examined species, and a cladistic analysis for groups of species are also included. New synonyms established: C. apacheanus Casey, 1891 = C. simulans Casey, 1907 syn. nov. = C. acuminatus Casey, 1907 syn. nov. = C. nobilis Casey, 1907 syn. nov.; C. approximatus Erichson, 1841 = C. aztecus Casey, 1907 syn. nov. = C. niger Pjatakowa, 1941 syn. nov.; C. attenuatus Erichson, 1841 = C. cuneatus Champion, 1894 syn. nov. = C. tenuis Champion, 1894 syn. nov.; C. aurulentus Candèze, 1874 = C. candezei Dohrn, 1881 syn. nov. = C. grossheimi Pjatakowa, 1941 syn. nov.; C. bomplandii Guérin, 1844 = C. humboldti Candèze, 1881 syn. nov.; C. chalcantheus Candèze, 1857 = C. violaceous Pjatakowa, 1941 syn. nov.; C. cyaneus Candèze, 1881 = C. scitus Candèze, 1889 syn. nov. = C. abbreviatovittatus Pjatakowa, 1941 syn. nov.; C. desmarestii Chevrolat, 1835 = C. brevicollis Casey, 1907 syn. nov.; C. gossipiatus Guérin, 1844 = C. erichsonii Guérin-Méneville, 1844 syn. nov. = C. lemoinii Candèze, 1857 syn. nov.; C. inops Candèze, 1886 = C. murinus Champion, 1894 syn. nov.; C. jansoni Candèze, 1874 = C. mucronatus Candèze, 1889 syn. nov.; C. lacordairii Candèze, 1857 = C. exquisitus Candèze, 1886 syn. nov. = C. monachus Candèze, 1893 syn. nov.; C. lenzi Candèze, 1886 = C. behrensi Candèze, 1886 syn. nov.; C. oxydatus Candèze, 1857 = C. jekeli Candèze, 1874 syn. nov.; C. porcatus (Linnaeus, 1767) = C. peruanus Candèze, 1886 syn. nov. = C. flavostriatus Pjatakowa, 1941 syn. nov. = C. herbstii multistriatus Golbach, 1977 syn. nov.; C. rugatus Candèze, 1857 = C. amictus Casey, 1907 syn. nov.; C. smaragdinus LeConte, 1854 = C. ostentus Casey, 1907 syn. nov. = C. rectus Casey, 1907 syn. nov.; C. sulcatus (Fabricius, 1777) = C. herbstii Erichson, 1841 syn. nov; C. virens (Fabricius, 1787) = C. perrisi Candèze, 1857 syn. nov.; C. virginalis Candèze, 1857 = C. championi Casey, 1907 syn. nov.; C. viridipilis (Say, 1825) = C. debilis Casey, 1907 syn. nov.; C. webbi LeConte, 1854 = C. sonoricus Casey, 1907 syn. nov.; C. zonatus Eschscholtz, 1829 = C. longicollis Candèze, 1857 syn. nov. New species described: C. albisetosus sp. nov. (Ecuador), C. albiventris sp. nov. (Mexico: Veracruz), C. copulatuvittatus sp. nov. (Venezuela), C. extenuatuvittatus sp. nov. (Venezuela), C. fasciatus sp. nov. (Mexico: Durango), C. ferratuvittatus sp. nov. (Ecuador), C. proximus sp. nov. (Mexico: Sinaloa), C. serricornis sp. nov. (Mexico: Veracruz), C. spinipennis sp. nov. (Mexico: Veracruz), C. supremus sp. nov. (Venezuela), C. truncuvittatus sp. nov. (Mexico: Tamaulipas) and C. virgatipennis sp. nov. (Mexico: Durango). Redescribed species: C. angustatus Candèze, 1857, C. apacheanus Casey, 1891, C. approximatus Erichson, 1841, C. attenuatus Erichson, 1841, C. aurulentus Candèze, 1874, C. bomplandii Guérin-Méneville, 1844, C. boucardi Candèze, 1874, C. chalcantheus Candèze, 1857, C. corpulentus Candèze, 1874, C. cyaneus Candèze, 1881, C. desmarestii Chevrolat, 1835, C. dugesi Candèze, 1886, C. erythroloma Candèze, 1857, C. eschscholtzi Chevrolat, 1833, C. exulatus Candèze, 1874, C. fabricii Erichson, 1841, C. forreri Candèze, 1886, C. fryi Candèze, 1874, C. gossipiatus Guérin-Méneville, 1844, C. inops Candèze, 1886, C. jansoni Candèze, 1874, C. lacordairii Candèze, 1857, C. lafargi Chevrolat, 1835, C. lenzi Candèze, 1886, C. limbatus (Fabricius, 1777), C. mexicanus Castelnau, 1836, C. mniszechi Candèze, 1881, C. mocquerysii Candèze, 1857, C. morio Candèze, 1857, C. obscurus Castelnau, 1836, C. oxydatus Candèze, 1857, C. porcatus (Linnaeus, 1767), C. pruinosus Erichson, 1841, C. rodriguezi Candèze, 1886, C. rostainei Candèze, 1889, C. rubripennis LeConte, 1861, C. rugatus Candèze, 1857, C. silbermanni Chevrolat, 1835, C. smaragdinus LeConte, 1854, C. sulcatus (Fabricius, 1777), C. tartarus Fall, 1898, C. validus Candèze, 1857, reval., C. villei Candèze, 1878, C. virens (Fabricius, 1787), C. virginalis Candèze, 1857, C. viridipilis (Say, 1825), C. webbi LeConte, 1854, C. zonatus Eschscholtz, 1829.

Taxonomia e morfologia de espécies neotropicais de Graphomya Robineau-Desvoidy (Diptera, Muscidae)

Graphomya Robineau-Desvoidy (Diptera, Muscidae) pode ser reconhecido por padrões cromáticos característicos no mesonoto e abdômen e pelas cerdas catepisternais 0:2. Das 14 espécies citadas na literatura para a Região Neotropical, sete são redescritas, com descrições das terminálias masculina e feminina - G. analis (Macquart), G. maculata (Scopoli), G. meridionalis Townsend, G. mexicana Giglio-Tos, G. occidentalis Arntfield, G. podexaurea(Enderlein) e G. tropicalis Malloch, aqui revalidada. Ilustrações coloridas do mesonoto e do abdômen são apresentadas para facilitar o reconhecimento das espécies. O neótipo de G. maculata é designado. A fêmea de G. podexaurea é registrada pela primeira vez. O registro geográfico das seguintes espécies é ampliado: G. meridionalis para o Equador e Peru; G. mexicana e G. podexaurea para o Brasil; G. tropicalis para Colômbia e Brasil.

Noctuidae moths occurring in grape orchards in Serra Gaúcha, Brazil and their relation to fruit-piercing

There is no study aiming to investigate if Noctuidae moths are responsible for piercing cultivated fruits in South America. This research aims to survey noctuid moths and list the species with mouth-parts (proboscis) morphology that suggest the capacity to cause damages to grape orchards in the state of Rio Grande do Sul, Brazil. Catches were carried out weekly from late November 2007 to late March 2008 (fructification period) using light traps and McPhail traps in three grape orchards in the region of Serra Gaúcha. The catches resulted in 187 taxa, with 149 identified at the specific level and 38 at genus level. The proboscises of representative taxa were removed and analyzed under stereomicroscope and scan electron microscope. It was verified that only Oraesia argyrosema (Hampson, 1926) and Gonodonta biarmata Guenée, 1852 show proboscis with suitable morphology for piercing rind and pulp of a grape berry. Achaea ablunaris (Guenée, 1852); Ascalapha odorata (Linnaeus, 1758); Letis mineis Geyer, 1827; Mocis latipes Hübner, 1823; Ophisma tropicalis Guenée, 1852, and Zale exhausta (Guenée, 1852) show proboscis only adapted to lacerate the pulp. The proboscis morphology of the remaining noctuid moths suggests lack of capacity to cause damage. Despite the presence of species capable of piercing grape berries, the populations of such species are very reduced and unable to cause damage of economic level.

Can sibling species of the Drosophila willistoni subgroup be recognized through combined microscopy techniques?

ABSTRACT In several arthropod groups, male genitalia is the most important feature for species identification, especially in cryptic species. Cryptic species are very common in the Drosophila genus, and the Neotropical Drosophila willistoni species group is a good example. This group currently includes 24 species divided into three subgroups: alagitans, bocainensis and willistoni. There are six sibling species in the willistoni subgroup – D. willistoni, D. insularis, D. tropicalis, D. equinoxialis, D. pavlovskiana and D. paulistorum, which is a species complex composed of six semispecies – Amazonian, Andean-Brazilian, Centroamerican, Interior, Orinocan and Transitional. The objective of this study was to characterize male genitalia of the willistoni subgroup, including the D. paulistorum species complex, using scanning electron microscopy and light microscopy. We also tried to contribute to the identification of these cryptic species and to add some comments about evolutionary history, based on male genitalia characters. Despite being cryptic species, some differences were found among the siblings, including the Drosophila paulistorum semispecies.

Homologous sex chromosomes in three deeply divergent anuran species.

Comparative genomic studies are revealing that, in sharp contrast with the strong stability found in birds and mammals, sex determination mechanisms are surprisingly labile in cold-blooded vertebrates, with frequent transitions between different pairs of sex chromosomes. It was recently suggested that, in context of this high turnover, some chromosome pairs might be more likely than others to be co-opted as sex chromosomes. Empirical support, however, is still very limited. Here we show that sex-linked markers from three highly divergent groups of anurans map to Xenopus tropicalis scaffold 1, a large part of which is homologous to the avian sex chromosome. Accordingly, the bird sex determination gene DMRT1, known to play a key role in sex differentiation across many animal lineages, is sex linked in all three groups. Our data provide strong support for the idea that some chromosome pairs are more likely than others to be co-opted as sex chromosomes because they harbor key genes from the sex determination pathway.

Crystal structure of yeast peroxisomal multifunctional enzyme: structural basis for substrate specificity of (3R)-hydroxyacyl-CoA dehydrogenase units.

(3R)-hydroxyacyl-CoA dehydrogenase is part of multifunctional enzyme type 2 (MFE-2) of peroxisomal fatty acid beta-oxidation. The MFE-2 protein from yeasts contains in the same polypeptide chain two dehydrogenases (A and B), which possess difference in substrate specificity. The crystal structure of Candida tropicalis (3R)-hydroxyacyl-CoA dehydrogenase AB heterodimer, consisting of dehydrogenase A and B, determined at the resolution of 2.2A, shows overall similarity with the prototypic counterpart from rat, but also important differences that explain the substrate specificity differences observed. Docking studies suggest that dehydrogenase A binds the hydrophobic fatty acyl chain of a medium-chain-length ((3R)-OH-C10) substrate as bent into the binding pocket, whereas the short-chain substrates are dislocated by two mechanisms: (i) a short-chain-length 3-hydroxyacyl group ((3R)-OH-C4) does not reach the hydrophobic contacts needed for anchoring the substrate into the active site; and (ii) Leu44 in the loop above the NAD(+) cofactor attracts short-chain-length substrates away from the active site. Dehydrogenase B, which can use a (3R)-OH-C4 substrate, has a more shallow binding pocket and the substrate is correctly placed for catalysis. Based on the current structure, and together with the structure of the 2-enoyl-CoA hydratase 2 unit of yeast MFE-2 it becomes obvious that in yeast and mammalian MFE-2s, despite basically identical functional domains, the assembly of these domains into a mature, dimeric multifunctional enzyme is very different.

First-generation linkage map for the European tree frog (Hyla arborea) with utility in congeneric species.

BACKGROUND: Western Palearctic tree frogs (Hyla arborea group) represent a strong potential for evolutionary and conservation genetic research, so far underexploited due to limited molecular resources. New microsatellite markers have recently been developed for Hyla arborea, with high cross-species utility across the entire circum-Mediterranean radiation. Here we conduct sibship analyses to map available markers for use in future population genetic applications. FINDINGS: We characterized eight linkage groups, including one sex-linked, all showing drastically reduced recombination in males compared to females, as previously documented in this species. Mapping of the new 15 markers to the ~200 My diverged Xenopus tropicalis genome suggests a generally conserved synteny with only one confirmed major chromosome rearrangement. CONCLUSIONS: The new microsatellites are representative of several chromosomes of H. arborea that are likely to be conserved across closely-related species. Our linkage map provides an important resource for genetic research in European Hylids, notably for studies of speciation, genome evolution and conservation.

Candida species distribution and antifungal susceptibility testing according to European Committee on Antimicrobial Susceptibility Testing and new vs. old Clinical and Laboratory Standards Institute clinical breakpoints: a 6-year prospective candidaemia survey from the fungal infection network of Switzerland.

We analyzed the species distribution of Candida blood isolates (CBIs), prospectively collected between 2004 and 2009 within FUNGINOS, and compared their antifungal susceptibility according to clinical breakpoints defined by the European Committee on Antimicrobial Susceptibility Testing (EUCAST) in 2013, and the Clinical and Laboratory Standards Institute (CLSI) in 2008 (old CLSI breakpoints) and 2012 (new CLSI breakpoints). CBIs were tested for susceptiblity to fluconazole, voriconazole and caspofungin by microtitre broth dilution (Sensititre(®) YeastOne? test panel). Of 1090 CBIs, 675 (61.9%) were C. albicans, 191 (17.5%) C. glabrata, 64 (5.9%) C. tropicalis, 59 (5.4%) C. parapsilosis, 33 (3%) C. dubliniensis, 22 (2%) C. krusei and 46 (4.2%) rare Candida species. Independently of the breakpoints applied, C. albicans was almost uniformly (>98%) susceptible to all three antifungal agents. In contrast, the proportions of fluconazole- and voriconazole-susceptible C. tropicalis and F-susceptible C. parapsilosis were lower according to EUCAST/new CLSI breakpoints than to the old CLSI breakpoints. For caspofungin, non-susceptibility occurred mainly in C. krusei (63.3%) and C. glabrata (9.4%). Nine isolates (five C. tropicalis, three C. albicans and one C. parapsilosis) were cross-resistant to azoles according to EUCAST breakpoints, compared with three isolates (two C. albicans and one C. tropicalis) according to new and two (2 C. albicans) according to old CLSI breakpoints. Four species (C. albicans, C. glabrata, C. tropicalis and C. parapsilosis) represented >90% of all CBIs. In vitro resistance to fluconazole, voriconazole and caspofungin was rare among C. albicans, but an increase of non-susceptibile isolates was observed among C. tropicalis/C. parapsilosis for the azoles and C. glabrata/C. krusei for caspofungin according to EUCAST and new CLSI breakpoints compared with old CLSI breakpoints.

Un gegant del cel en perill d'extinció : socialització i divulgació de la reintroducció del voltor negre a Catalunya

La interacció de l’home amb les diferents espècies amb les quals cohabita ha creat casos com el del Voltor Negre (Aegypius monachus), l’au necròfaga més gran d’Europa, que actualment es troba en perill d’extinció. La utilització del territori per a ús antropogènic (ramaderia, xarxes elèctriques, zones urbanes,...) ha fet disminuir la població d’aquesta espècie. Així com la incursió, de manera indirecta, en aquestes poblacions degut a l’acció de l’home podem destacar-ne’n dos, el més rellevant és la intoxicació per verí, degut a l’ús il·legal d’aquestes substàncies per al control de depredadors fa que els tòxics vagin pujant per la piràmide tròfica. La segona causa rellevant és la disminució d’aliment degut a la mixomatosis i a la normativa existent d’obligatorietat de retirada dels animals morts a muntanya per sota dels 1400m. Al fer l’anàlisi de problemàtiques, s’observa que la gran majoria són antròpiques, degudes a la desinformació i al desconeixement, per tant; per a realitzar un bon pla de reintroducció és necessari fer un treball previ de socialització de les poblacions de la zona per a que el projecte sigui eficient. El projecte consisteix en fer una conscienciació social als diferents grups implicats (turisme, escoles i població; ramaders i caçadors), mitjançant documents gràfics, material educatiu, material de suport i materials i mètodes de divulgació. Per a que la vall d’Alinyà i Boumort passin a ser destacades per la presencia establerta de les quatre aus necròfagues més rellevants d’Europa; l’Aufrany, el Trencalòs, el voltor comú i el nostre protagonista: el Voltor Negre.

Anàlisi socioambiental dels voltors a Alinyà : evolució, percepció i viabilitat

La finca de la Muntanya d’Alinyà és l’única zona del món on es poden observar les quatre espècies de voltors europeus: voltor comú (Gyps fulvus), voltor negre (Aegypius monachus), aufrany (Neophron percnopterus) i trencalòs (Gypaetus barbatus). Davant el problema de l’abandonament del poble i de l’envelliment de la població es planteja una alternativa de futur vers a una economia no tant basada en la ramaderia i l’agricultura, que són les activitats agropecuàries tradicionals a la zona. La recent intervenció de la Fundació Territori i Paisatge ha determinat, en gran part, el futur d’aquestes aus a Alinyà. Per una altra banda, les normatives vigents eren molt restrictives, fins fa ben poc, sobre l’aprofitament per part dels voltors de les restes d’animals morts provinents de la ramaderia. Ara neix una nova perspectiva de futur de tipus turístic.

Prolonged fluconazole exposure leads to a shift to Candida species with decreased susceptibility in breakthrough candidemia: prospective survey of the Fungal Infection Network of Switzerland

Objectives: To compare the clinical characteristics, species distribution and antifungal susceptibility of Candida bloodstream isolates (BSI) in breakthrough (BTC) vs. non-breakthrough candidemia (NBTC) and to study the effect of prolonged vs. short fluconazole (F) exposure in BTC.Methods: Candida BSI were prospectively collected during 2004- 2006 from 27 hospitals (seven university, 20 affiliated) of the FUNGINOS network. Susceptibility to F, voriconazole (V) and caspofungin (C) was tested in the FUNGINOS mycology reference laboratory by microtitre broth dilution method with the Sensititre YeastOneTM test panel. Clinical data were collected using standardized CRFs. BTC was defined as occurring during antifungal treatment/prophylaxis of at least three days duration prior to the candidemia. Susceptibility of BSI was defined according to 2010/2011 CLSI clinical breakpoints.Results: Out of 567 candidemia episodes, 550 Candida BSI were available. Of these, 43 (7.6%) were from BTC (37/43, 86% were isolated after F exposure). 38 BTC (88.4%) and 315 NBTC (55.6%) occurred in university hospitals (P < 0.001). The majority of patients developing BTC were immunocompromised: higher proportions of haematological malignancies (62.8% in BTC vs. 47.1% in NBTC, P < 0.001), neutropenia (37.2% vs. 11.8%, P < 0.001), acute GvHD (14% vs. 0.2%, P < 0.001), immunosuppressive drugs (74.4% vs. 7.8%, P < 0.001), and mucositis (32.6% vs. 2.3%, P < 0.001) were observed. Other differences between BTC and NBTC were higher proportions of patients with central venous catheters in the 2 weeks preceding candidemia (95.3% vs. 83.4%, P = 0.047) and receiving total parenteral nutrition (62.8% vs. 35.9%, P < 0.001), but a lower proportion of patients treated with gastric proton pump inhibitors (23.3% vs. 72.1%, P < 0.001). Overall mortality of BTC and NBTC was not different (34.9% vs. 31.7%, P = 0.73), while a trend to higher attributable mortality in BTC was found (13.9% vs. 6.9%, P = 0.12). Species identification showed a majority of C. albicans in both groups (51.2% in BTC vs. 62.9% in NBTC, P = 0.26), followed by C. glabrata (18.6% vs. 18.5%), C. tropicalis (2.3% vs. 6.3%) and C. parapsilosis (7.0% vs. 4.7%). Significantly more C. krusei were detected in BTC versus NBTC (11.6% vs. 1.6%, P = 0.002). The geometric mean MIC for F, V and C between BTC and NBTC isolates was not significantly different. However, in BTC there was a significant association between duration of F exposure and the Candida spp.: >10 days of F was associated with a significant shift from susceptible Candida spp. (C. albicans, C. parapsilosis, C. tropicalis, C. famata) to non-susceptible species (C. glabrata, C. krusei, C. norvegensis). Among 21 BTC episodes occurring after £10 days of F, 19% of the isolates were non-susceptible, in contrast to 68.7% in 16 BTC episodes occurring after >10 days of F (P = 0.003).Conclusions: Breakthrough candidemia occurred more often in immunocompromised hosts. Fluconazole administered for >10 days was associated with a shift to non-susceptible Candida spp.. Length of fluconazole exposure should be taken into consideration for the choice of empirical antifungal treatment.

Germination, senescence and pathogenic attack in soybean (Glycine max. L.): Identification of the cytosolic aconitase participating in the glyoxylate cycle

During our study of the glyoxylate cycle in soybean (Glycine max. L. var. Maple arrow), two mitochondrial and three cytosolic aconitase molecular species (EC 4.2.1.3) were detected, designated as M1, M2, C1, C2 and C3 isoforms, respectively, according to their intracellular locations and electrophoretic mobilities. Using the glyoxylate cycle marker enzymes isocitrate lyase (ICL, EC 4.1.3.1) and malate synthase (MS, EC 4.1.3.2), the activity of this pathway providing the essential link between P-oxidation and gluconeogenesis was confirmed during germination (cotyledons) and senescence (leaves). It was then established that, in both cases, the activity of the CI aconitase isoform developed concomitantly with the transcription and translation levels of the icl and ms genes. This strongly suggests that C1 aconitase is constitutive of the glyoxylate cycle. In addition, the same isoform was found to be active during pathogenic attack as well (hypocotyls). It might be assumed that in such a case the glyoxylate cycle is reinitiated as a part of a carbon reallocation system feeding on the diseased tissue cellular components.

Stable isotopes unveil habitat partitioning among the marine mammals off NW Africa and reveal unique trophic niches for two globally threatened species.

Stable isotope abundances of carbon (δ13C) and nitrogen (δ15N) in the bone of 13 species of marine mammals from the northwest coast of Africa were investigated to assess their positions in the local trophic web and their preferred habitats. Also, samples of primary producers and potential prey species from the study area were collected to characterise the local isotopic landscape. This characterisation indicated that δ13C values increased from offshore to nearshore and that δ15N was a good proxy for trophic level. Therefore, the most coastal species were Monachus monachus and Sousa teuszii, whereas the most pelagic were Physeter macrocephalus and Balaenoptera acutorostrata. δ15N values indicated that marine mammals located at the lowest trophic level were B. acutorostrata, Stenella coeruleoalba and Delphinus sp., and those occupying the highest trophic level were M. monachus and P. macrocephalus. The trophic level of Orcinus orca was similar to that of M. monachus, suggesting that O. orca preys on fish. Conservation of coastal and threatened species (M. monachus and S. teuszii) off NW Africa should be a priority because these species, as the main apex predators, cannot be replaced by other marine mammals.

High-density linkage maps fail to detect any genetic component to sex determination in a Rana temporaria family.

Sex chromosome differentiation in Rana temporaria varies strikingly among populations or families: whereas some males display well-differentiated Y haplotypes at microsatellite markers on linkage group 2 (LG2 ), others are genetically undistinguishable from females. We analysed with RADseq markers one family from a Swiss lowland population with no differentiated sex chromosomes, and where sibship analyses had failed to detect any association between the phenotypic sex of progeny and parental haplotypes. Offspring were reared in a common tank in outdoor conditions and sexed at the froglet stage. We could map a total of 2177 SNPs (1123 in the mother, 1054 in the father), recovering in both adults 13 linkage groups (= chromosome pairs) that were strongly syntenic to Xenopus tropicalis despite > 200 My divergence. Sexes differed strikingly in the localization of crossovers, which were uniformly distributed in the female but limited to chromosome ends in the male. None of the 2177 markers showed significant association with offspring sex. Considering the very high power of our analysis, we conclude that sex determination was not genetic in this family; which factors determined sex remain to be investigated.

High-density sex-specific linkage maps of a European tree frog (Hyla arborea) identify the sex chromosome without information on offspring sex.

Identifying homology between sex chromosomes of different species is essential to understanding the evolution of sex determination. Here, we show that the identity of a homomorphic sex chromosome pair can be established using a linkage map, without information on offspring sex. By comparing sex-specific maps of the European tree frog Hyla arborea, we find that the sex chromosome (linkage group 1) shows a threefold difference in marker number between the male and female maps. In contrast, the number of markers on each autosome is similar between the two maps. We also find strongly conserved synteny between H. arborea and Xenopus tropicalis across 200 million years of evolution, suggesting that the rate of chromosomal rearrangement in anurans is low. Finally, we show that recombination in males is greatly reduced at the centers of large chromosomes, consistent with previous cytogenetic findings. Our research shows the importance of high-density linkage maps for studies of recombination, chromosomal rearrangement and the genetic architecture of ecologically or economically important traits.