Zhijuan Nie

Molecular characterization and differential expression of the myostatin gene in Coilia nasus

Estuarine tapertail anchovy (Coilia nasus, junior synonym C. ectenes) is a widely distributed and commercially important aquaculture species, although its growth in aquaculture settings is so slow as to pose a serious practical problem. In order to understand the molecular mechanisms of growth, we cloned the myostatin gene in C. nasus (CnMSTN) by homologous cloning methods. Its full-length cDNA is 2252 bp, with a 1125-bp open reading frame (ORF) that encodes a 374-amino acid protein. The CnMSTN protein is predicted to contain domains typical of MSTN, including a TGFb-propeptide domain and a TGFB domain. Gene expression patterns were detected by RT-qPCR. CnMSTN is expressed strongly in the muscle and brain, and comparatively lower in the gills, liver, spleen, intestine, trunk kidney and head kidney. The effects of stress on the muscle and brain MSTN levels were evaluated by RT-qPCR. CnMSTN in the muscle was positively regulated by loading and transport stress, but brain CnMSTN expression was not affected. We found NaCl could reduce the death rate caused by loading and transporting stress, and in this group, CnMSTN mRNA expression in the muscle revealed increased, but decreased in the brain. Further, in the fasting experiment, the CnMSTN mRNA revealed decrease in the muscle, on the contrary, it showed increase in the brain. Selection upon variants of the MSTN gene has shown great potential in breeding work for mammals, and our results provide the basic knowledge for breeding of C. nasus.

Complete mitochondrial genome of Caridina nilotica gracilipes

Abstract In this study, we sequenced the complete mitochondrial genome of Caridina nilotica gracilipes. This mitochondrial genome, consisting of 15,550 base pairs, encoded 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs, and a non-coding control region as those found in other Decapoda, with the gene synteny identical to that of typical invertebrates. Control region (D-Loop), of 673 bp in length, is located between 12S rRNA and tRNAIle. The overall base composition of the heavy strand shows T 30.4%, C 22.0%, A 33.0% and G 14.6%, with an AT bias of 63.4%.

Monogonont Rotifer, Brachionus calyciflorus, Possesses Exceptionally Large, Fragmented Mitogenome

In contrast to the highly conserved mitogenomic structure and organisation in most animals (including rotifers), the two previously sequenced monogonont rotifer mitogenomes were fragmented into two chromosomes similar in size, each of which possessed one major non-coding region (mNCR) of about 4–5 Kbp. To further explore this phenomenon, we have sequenced and analysed the mitogenome of one of the most studied monogonont rotifers, Brachionus calyciflorus. It is also composed of two circular chromosomes, but the chromosome-I is extremely large (27 535 bp; 3 mNCRs), whereas the chromosome-II is relatively small (9 833 bp; 1 mNCR). With the total size of 37 368 bp, it is one of the largest metazoan mitogenomes ever reported. In comparison to other monogononts, gene distribution between the two chromosomes and gene order are different and the number of mNCRs is doubled. Atp8 was not found (common in rotifers), and Cytb was present in two copies (the first report in rotifers). A high number (99) of SNPs indicates fast evolution of the Cytb-1 copy. The four mNCRs (5.3–5.5 Kb) were relatively similar. Publication of this sequence shall contribute to the understanding of the evolutionary history of the unique mitogenomic organisation in this group of rotifers.

Complete mitochondrial genome of Paracanthobrama guichenoti

Abstract In this study, we sequenced the complete mitochondrial genome of Paracanthobrama guichenoti. This mitochondrial genome, consisting of 16,607 base pairs, encoded 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs, and a non-coding control region as those found in other vertebrates, with the gene synteny identical to that of typical vertebrates. Control region (D-Loop), of 932 bp in length, is located between tRNAPhe and tRNALeu. The overall base composition of the heavy strand shows T 28.4%, C 24.6%, A 31.2% and G 15.7%, with an AT bias of 59.6%.