Rana neba was originally described based mainly on karyological and acoustic characteristics; however, no comprehensive species delimitation studies have been conducted since its description. Through analyses of nuclear genome data, karyotypes, and mating calls, we found that the geographic distributions inferred from the two diagnostic traits conventionally used to define R. neba—the presence of 28 chromosomes and a unique mating call—are inconsistent with each other. Moreover, neither of the two traits corresponds to the genetic structures inferred from SNPs or mtDNA data. These findings indicate that the current diagnostic traits should no longer be used for the species delimitation of R. neba. Nonetheless, phylogenetic relationships clearly show that R. neba does not correspond to any previously recognized species. Accordingly, we tentatively propose that the name R. neba be assigned to the genetic group distributed in the southern part of Chubu region (Group A). The observed variation in chromosome number is likely an intraspecific polymorphism. This group is both genetically and geographically continuous with other groups, which we designate as Groups B and C (the latter including the topotypic specimen of R. kyoto). Further taxonomic studies are necessary to clarify the species boundaries between these groups and Group A. Additionally, the taxonomic status of other populations belonging to Cluster II of the R. tagoi complex—specifically, those from the Izu Peninsula, northern Kanto, and the Tohoku region—should also be re-evaluated in future studies.
This study evaluated the influence of body condition indices and climatic parameters on gametogenesis in Pithecopus gonzagai from two Brazilian morphoclimatic domains. Individuals were sampled monthly at the Tapacurá Ecological Station (Atlantic Forest) and the Olho D'Água da Bica Forest Garden (Caatinga). Body condition was assessed using the condition factor (K1) and gonadosomatic, hepatosomatic, and liposomatic indices calculated from body and tissue masses. Gonadal histology was performed to characterize gametogenesis and reproductive activity. Significant temporal variation was detected in some somatic indices, particularly among males from both domains. Histological analyses revealed all stages of spermatogenesis and oogenesis, indicating prolonged reproductive activity throughout most of the sampling period. Significant temporal variation in spermatogenic cell densities was observed in the Atlantic Forest population. Correlation analyses revealed significant associations between specific germ cell types and climatic variables, including precipitation, humidity, and temperature, although the magnitude and direction of these relationships differed between populations. Overall, the results suggest that environmental conditions may influence physiological and reproductive traits in P. gonzagai, while reproductive activity appears to occur throughout most of the annual cycle in both populations.
A new troglobitic dipluran species of the campodeid genus Pacificampa Chevrizov, 1978, P. dodecas sp. nov., collected from four caves in Akiyoshidai district, Yamaguchi Prefecture, Japan, is described. This new species is clearly distinguishable from other congeners by the following characteristics: body size, macrosetae distribution on the mesonotum and tergite, and the ratio of the antenna length to the body length. Additionally, partial sequences of the mitochondrial cytochrome c oxidase subunit I gene extracted from specimens collected from the four caves support the con-specificity of the populations, which form a lineage distinct from those of other Japanese Pacificampa species. Although the phylogenetic position of Pacificampa remains unclear, the present phylogeny based on the 18S rRNA gene indicates a close relationship between Pacificampa and the campodeid genus Metriocampa Silvestri, 1911. Furthermore, the present molecular phylogeny suggests the non-monophyly of the subfamily Campodeinae.
Black rhinoceros (Diceros bicornis) is critically threatened with extinction in the wild due to illegal horn poaching and habitat loss. Captive breeding programs for this species have become crucial insurance for endangered wild populations. Understanding the geographical origin of captive black rhinoceros in Japan and revealing their genetic diversity can aid breeding and conservation strategies. This study included nearly all available individuals in Japan to evaluate their genetic diversity and geographical origin. DNA samples of 21 animals were extracted from samples provided by 10 Japanese zoos. We analyzed haplotypes of the mtDNA D-loop (477 bp) and the diversity of 11 microsatellite (STR) loci, comparing them with previous reports on African wild populations. Our results indicated that the Japanese captive population has slightly smaller genetic diversity (h = 0.65) compared to other populations (h = 0.72–0.94) in mtDNA D-loop, while STR markers maintain diversity (Ho = 0.66) similar to that of the African wild populations (Ho = 0.66). Among four haplotypes found, one and three haplotypes of mtDNA D-loop matched sequences from the Southern and Eastern African haplogroups, respectively. The combination of mtDNA and STR data leads to the conclusion that the Japanese population likely originated from Kenya, Tanzania, and the Democratic Republic of Congo. The genetic diversity of black rhinoceros in Japan is considered satisfactory, with the potential to further enhance genetic variation among breeding combinations without needing external supplementation. Based on these results, caution should be exercised when selecting this population for international translocation or reintroduction to safeguard captive breeding of the species.
Several neuropeptides are reported to function in the immune system of teleost fish. Prolactin-releasing peptide-2 (PrRP2) is thought to be a local modulator of the innate immune response in leukocytes of Atlantic salmon, Salmo salar. We selected the common carp, Cyprinus carpio, as a model organism and examined PrRP2 gene expression in blood cells using reverse transcription polymerase chain reaction (RT-PCR) and DNA sequencing. We also investigated the presence of the PrRP2 peptide using immunocytochemistry. The expression of several other neuropeptides, corticotropin-releasing hormone (CRH), gonadotropin-releasing hormone (GnRH2 and GnRH3), melanin-concentrating hormone (MCH), neuropeptide Y (NPY), orexin (ORX), and thyrotropin-releasing hormone (TRH) was also investigated in blood cells. To account for the possible effects of background color on neuropeptide gene expression, fish were reared on black or white backgrounds for 21 days. PrRP2 expression was observed in blood cells of all individuals. PrRP2 immunoreactivity was detected in granulocytes, lymphocytes, and some unidentified cells. Gene expression of the other neuropeptides, except for GnRH2, was also detected and was not significantly different between fish reared with either background. Our study is the first to demonstrate that several neuropeptides are expressed in blood cells of the common carp.
