Authorship：Lead author   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

Abstract

Blindsnakes of infraoder Scolecophidia (order Squamata) are the most basal group of extant snakes, comprising of more than 450 species with ecological and morphological features highly specialized to underground living. The Brahminy blindsnake, Indotyphlops braminus, is the only known obligate parthenogenetic species of snakes. Although the origin of I. braminus is thought to be South Asia, this snake has attracted worldwide attention as an alien species, as it has been introduced to all continents except Antarctica. In this study, we present the first draft genome assembly and annotation of I. braminus. We generated approximately 480 Gbp of sequencing data and produced a draft genome with a total length of 1.86 Gbp and N50 scaffold size of 1.25 Mbp containing 89.3% of orthologs conserved in Sauropsida. We also identified 0.98 Gbp (52.82%) of repetitive genome sequences and a total of 23,560 protein-coding genes. The first draft genome of I. braminus will facilitate further study of snake evolution as well as help to understand the emergence mechanism of parthenogenetic vertebrates.

DOI： 10.1038/s41597-022-01530-z

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Other Link： https://www.nature.com/articles/s41597-022-01530-z

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Oxford University Press ({OUP})  

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<jats:p>Horizontal transfer (HT) of genes between multicellular animals, once thought to be extremely rare, is being more commonly detected, but its global geographic trend and transfer mechanism have not been investigated. We discovered a unique HT pattern of Bovine-B (BovB) LINE retrotransposons in vertebrates, with a bizarre transfer direction from predators (snakes) to their prey (frogs). At least 54 instances of BovB HT were detected, which we estimate to have occurred across time between 85 and 1.3 Ma. Using comprehensive transcontinental sampling, our study demonstrates that BovB HT is highly prevalent in one geographical region, Madagascar, suggesting important regional differences in the occurrence of HTs. We discovered parasite vectors that may plausibly transmit BovB and found that the proportion of BovB-positive parasites is also high in Madagascar where BovB thus might be physically transported by parasites to diverse vertebrates, potentially including humans. Remarkably, in two frog lineages, BovB HT occurred after migration from a non-HT area (Africa) to the HT hotspot (Madagascar). These results provide a novel perspective on how the prevalence of parasites influences the occurrence of HT in a region, similar to pathogens and their vectors in some endemic diseases.</jats:p>

DOI： 10.1093/molbev/msac052

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Informa {UK} Limited  

The complete sequence of the mitochondrial genome (mitogenome) of Tachysurus nudiceps (family Bagridae; order Siluriformes) was determined using next-generation sequencing. The composition of its mitogenome is the same as that observed in most other vertebrates and consists of 37 genes, an L-strand replication origin and a control region. As in previous studies, our phylogenetic analyses revealed that many of the bagrid genera are not monophyletic, emphasizing the necessity for reviewing and revising the taxonomy of this family at the genus level.

DOI： 10.1080/23802359.2022.2057253

PubMed

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Pleiades Publishing Ltd  

DOI： 10.1134/s0032945222020072

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Other Link： https://link.springer.com/article/10.1134/S0032945222020072/fulltext.html

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

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Authorship：Lead author   Publishing type：Research paper (scientific journal)   Publisher：The Biological Society of Washington  

DOI： 10.2988/20-00003

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：HINDAWI LTD  

The mitochondrial (mt) genome of the bushveld rain frog (Breviceps adspersus, Brevicipitidae, Afrobatrachia) is the largest (28.8 kbp) among the vertebrates investigated to date. The major cause of genome size enlargement in this species is the duplication of multiple genomic regions. To investigate the evolutionary lineage, timing, and process of mt genome enlargement, we sequenced the complete mtDNAs of two congeneric rain frogs, B. mossambicus and B. poweri. The mt genomic organization, gene content, and gene arrangements of these two rain frogs are very similar to each other but differ from those of B. adspersus. The B. mossambicus mt genome (22.5 kbp) does not differ significantly from that of most other afrobatrachians. In contrast, the B. poweri mtDNA (28.1 kbp) is considerably larger: currently the second largest among vertebrates, after B. adspersus. The main causes of genome enlargement differ among Breviceps species. Unusual elongation (12.5 kbp) of the control region (CR), a single major noncoding region of the vertebrate mt genome, is responsible for the extremely large mt genome in B. poweri. Based on the current Breviceps phylogeny and estimated divergence age, it can be concluded that the genome enlargements occurred independently in each species lineage within relatively short periods. Furthermore, a high nucleotide substitution rate and relaxation of selective pressures, which are considered to be involved in changes in genome size, were also detected in afrobatrachian lineages. Our results suggest that these factors were not direct causes but may have indirectly affected mt genome enlargements in Breviceps.

DOI： 10.1155/2020/6540343

Web of Science

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media {LLC}  

DOI： 10.1007/s00436-018-6141-y

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Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.15027/34533

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Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.15027/45330

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Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)  

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Authorship：Lead author   Language：Japanese  

DOI： 10.15027/43823

CiNii Article

CiNii Books

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Other Link： http://ir.lib.hiroshima-u.ac.jp/00043823

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