We know little about the process of spermatogenesis in bats, a great and diverse clade of mammals that presents different reproductive strategies. In the present study, spermatogenesis in six species of Neotropical bats was investigated by light microscopy. On the basis of chromatin condensation, nuclear morphology, relative position to the basal membrane and formation of the flagellum, three types of spermatogonia were recognized: dark type A (A(d)), pale type A (A(p)), and type B; the development of spermatids was divided into seven steps. With the exception of Myotis nigricans, the seminiferous epithelium cycle of the other five species studied was similar to those of other mammals, showing gradual stages by the tubular morphology method. Asynchrony was observed in the seminiferous epithelium cycle of M. nigricans, shown by overlapping stages and undefined cycles. The frequencies found in the three phases of the cycle were variable with the greatest frequency occurring in the postmeiotic phase (>50%) and the least in the meiotic phase (<10%). The similarities observed in the five species of Phyllostomidae appeared to be related to their phylogenetic relationship and shorter divergence times, whereas the differences in M. nigricans appeared to be related to its greater phylogenetic distance because the Vespertilionidae family diverged earlier.
ABSTRACT. Molossidae species, Cynomops abrasus (2n = 34, fundamental number, FN = 64), Eumops auripendulus (2n = 42, FN = 62), Molossus rufus (2n = 48, FN = 64), Molossops temminckii (2n = 48, FN = 64), and Nyctinomops laticaudatus (2n = 48, FN = 64), and Phyllostomidae species, Phyllostomus discolor (2n = 32, FN = 60), have karyotypes with different chromosome and fundamental numbers, different localization of constitutive heterochromatin, and different numbers and location of nucleolar organizer regions (NORs). Fluorescence in situ hybridization with a human probe of the telomeric sequence (TTAGGG) n produced fluorescent signals in telomeric regions of the six bat species' chromosomes; in E. auripendulus, pericentromeric signals were also observed in the acrocentric and subtelocentric chromosomes. A relationship between telomeric sequences and NORs, and
ABSTRACT.We made the first analysis of the COI gene sequences of 22 species of spittlebugs and aquatic true bugs sampled in São Paulo State (Brazil) and used this information to determine the variability within these groups. Considering each codon position, we observed that the third base was the most variable, and the first base was the most conserved. Among species, Mahanarva fimbriolata and Deois flavopicta had the greatest genetic distance (0.181), and Notozulia entreriana and Mahanarva sp had the smallest distance (0.055), with an average variation of 0.119. In Gerromorpha, the Haplotypes from COI in spittlebugs and true bugs greatest distance occurred between Halobatopsis platensis and Rhagovelia zela (0.401), while between Cylindrostethus palmaris and Brachymetra albinervis albinervis, the distance was only 0.187; the average value observed for the Gerromorpha was 0.265. In the Nepomorpha, the species Buenoa antigone antigone and Belostoma micantulum had the greatest genetic distance (0.337), while Martarega brasiliensis and B. a. antigone had the smallest (0.154). The average value observed for Nepomorpha was 0.203. In Cicadomorpha (Auchenorrhyncha) and Nepomorpha (Heteroptera), the COI gene has been conserved; however, it is still useful for characterization of the different taxa. COI analysis was unable to resolve some of the Gerromorpha groups.
ABStRACt.A PCR-RFLP analysis of the restriction pattern in nuclear (RAG2) and mitochondrial (12S/16S) gene sequences of bat species from the Molossidae, Phyllostomidae, Vespertilionidae, and Emballonuridae families produced a large number of fragments: 107 for RAG2 and 155 for 12S/16S combined in 139 and 402 haplotypes, respectively. The values detected for gene variation Genetic variability in bats were low for both sequences (0.13 for RAG2 and 0.15 for 12S/16S) and reflected their conservative feature, reinforced by high values of inter-and intraspecies genetic identity (70-100%). The species with a high gene divergence were variable in the analyses of RAG2 (Eumops perotis, Artibeus lituratus, and Carollia perspicillata) and of 12S/16S (Nyctinomops laticaudatus, C. perspicillata, and Cynomops abrasus), and furthermore, one of them, C. perspicillata, also showed the highest intraspecific variation. The species that exhibited the lowest variation for both genes was Molossus rufus. In the families, the highest variation was observed in the Molossidae and this can be attributed to variation exhibited by Eumops and Nyctinomops species. The variations observed were interpreted as a natural variability within the species and genus that exhibited a conserved pattern in the two gene sequences in different species and family analyzed. Our data reinforce the idea that the analyses of mitochondrial and nuclear genes contribute to our knowledge of the diversity of New World bats. The genetic variability found in different taxa suggests that an additional diversity, unnoticed by other methods, can be revealed with the use of different molecular strategies.
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