Bai Chao, Wu Yunfei, Merchant Austin, Xie Danjie, Cao Jie, Wang Qinghua, Zhou Xuguo
Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing, 100091, China.
Beijing Xinhai Garden Engineering Co., LTD, Beijing, China.
Funct Integr Genomics. 2023 Jan 18;23(1):41. doi: 10.1007/s10142-022-00959-0.
The complete mitochondrial genome (mitogenome) of the sawfly, Nesodiprion zhejiangensis Zhou & Xiao, was sequenced, assembled, and deposited in GenBank (Accession Number: OM501121). The 15,660 bp N. zhejiangensis mitogenome encodes for 2 ribosomal RNAs (rrnL and rrnS), 22 transfer RNAs (tRNAs), 13 protein-coding genes (PCGs), and an AT-rich region of 450 bp in length. The nucleotide composition is biased toward adenine and thymine (A + T = 81.8%). Each PCG is initiated by an ATN codon, except for cox2, which starts with a TTG. Of 13 PCGs, 9 have a TAA termination codon, while the remainder terminate with a TAG or a single T. All tRNAs have the classic cloverleaf structure, except for the dihydrouridine (DHU) arm of tRNA, which forms a simple loop. There are 49 helices belonging to 6 domains in rrnL and 30 helices belonging to 4 domains in rrnS. In comparison to the ancestral architecture, N. zhejiangensis has the most rearranged mitogenome in Symphyta, in which rearrangement events of local inversion and transposition are identified in three gene clusters. Specifically, the main hotspot of gene rearrangement occurred between rrnS and trnY, and rearranged from rrnS-(AT-rich region)-I-Q-M-nd2-W-C-Y to rrnS-Q-W-C-nd2-I-M-(AT-rich region)-Y, involving a local inversion event of a large gene cluster and transposition events of some tRNAs. Transposition of trnA and trnR (rearranged from A-R to R-A) was observed at the nd3-nd5 gene junction while shuffling of trnP and trnT (rearranged from T-P to P-T) occurred at the nd4l-nd6 gene junction. While illegitimate inter-mtDNA recombination might explain the opposite orientations of transcription between rrnS and trnY, transposition events of tRNA in some gene blocks can be accounted for by the tandem duplication/random loss (TDRL) model. Our phylogenetic analysis suggests that N. zhejiangensis is closely related to congeneric species N. biremis and N. japonicus, which together form a sister lineage with the European pine sawfly, Neodiprion sertifer.
浙江黑松叶蜂（Nesodiprion zhejiangensis Zhou & Xiao）的完整线粒体基因组（线粒体基因组）已被测序、组装并提交至GenBank（登录号：OM501121）。浙江黑松叶蜂的线粒体基因组全长15,660 bp，编码2个核糖体RNA（rrnL和rrnS）、22个转移RNA（tRNA）、13个蛋白质编码基因（PCG）以及一个长度为450 bp的富含AT的区域。核苷酸组成偏向腺嘌呤和胸腺嘧啶（A + T = 81.8%）。每个PCG均由ATN密码子起始，但cox2除外，其起始密码子为TTG。在13个PCG中，9个具有TAA终止密码子，其余的则以TAG或单个T终止。所有tRNA均具有经典的三叶草结构，但tRNA的二氢尿嘧啶（DHU）臂形成一个简单的环。rrnL中有49个属于6个结构域的螺旋，rrnS中有30个属于4个结构域的螺旋。与祖先结构相比，浙江黑松叶蜂在线叶蜂类中具有最复杂的线粒体基因组重排，其中在三个基因簇中鉴定出局部倒位和转座的重排事件。具体而言，基因重排的主要热点发生在rrnS和trnY之间，从rrnS-(富含AT的区域)-I-Q-M-nd2-W-C-Y重排为rrnS-Q-W-C-nd2-I-M-(富含AT的区域)-Y，涉及一个大基因簇的局部倒位事件和一些tRNA的转座事件。在nd3-nd5基因连接处观察到trnA和trnR的转座（从A-R重排为R-A），而在nd4l-nd6基因连接处发生了trnP和trnT的洗牌（从T-P重排为P-T）。虽然非法的线粒体DNA间重组可能解释rrnS和trnY之间转录方向的相反，但某些基因块中tRNA的转座事件可以用串联重复/随机丢失（TDRL）模型来解释。我们的系统发育分析表明，浙江黑松叶蜂与同属物种双叉黑松叶蜂（N. biremis）和日本黑松叶蜂（N. japonicus）密切相关，它们共同形成一个姐妹谱系，与欧洲松叶蜂（Neodiprion sertifer）构成姐妹群。
