Two types of gynogenetic blunt snout bream derived from different sperm
Two types of gynogenetic blunt snout bream derived from different sperm
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来自不同精子的两种雌核发育钝口鳊鱼
DOI：
10.1016/j.aquaculture.2019.734250
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发表时间：
2019-09-15
期刊：
影响因子：
4.5
通讯作者：
Liu, Shaojun
中科院分区：
文献类型：
--
作者：
Gong, Dingbin;Xu, Lihui;Liu, Shaojun
团头鲂（Megalobrama amblycephala，2n = 48，BSB）是一种重要的经济鱼类，但耐缺氧能力较差。雌核发育是获得耐缺氧能力更强的BSB的有效途径。本研究以锦鲤（Cyprinus carpio haematopterus，2n = 100，KOC）和翘嘴卡尔特（Erythro卡尔特ilishaeformis，2n = 48，TC）的精子为材料，分别进行紫外线辐射激活BSB卵。经冷休克使染色体加倍，获得两种雌核发育型BSB（简称GBSB-K和GBSB-T）。比较分析BSB、GBSB-K和GBSB-T的形态特征、DNA含量和染色体数，差异不显著（p > 0.05）。而微卫星（Cca 15-K、Cca 15-T）分析结果显示，在GBSB-K和GBSB-T中检测到了父本DNA片段。这些特异DNA片段是鉴别雌核发育型BSB和BSB的有价值的分子标记。实验结果表明，GBSB-K和GBSB-T的耐缺氧能力明显高于BSB（p < 0.05）。KOC和TC都是诱导BSB雌核发育并形成“杂种”效应的有效刺激物。冷休克、辐照精子存活率低、异源精子“杂种”效应等因素可能产生较强的雌核发育BSB，并具有较强的耐缺氧能力。这两种异源精子形成的雌核发育BSB在鱼类遗传育种中具有重要意义。
Blunt snout bream (Megalobrama amblycephala, 2n = 48, BSB) is an important fish species with great commercial value but has a shortcoming in hypoxia tolerance. Gynogenesis is an effective way to obtain improved BSB with a higher ability to tolerate hypoxia. In this study, BSB eggs were activated by UV-irradiated sperm of koi carp (Cyprinus carpio haematopterus, 2n = 100, KOC) and topmouth culter (Erythroculter ilishaeformis, 2n = 48, TC), respectively. Following cold shock to double the chromosomes, two types of gynogenetic BSB (abbreviated as GBSB-K and GBSB-T) were obtained. Comparative analyses regarding the morphological characteristics, DNA content and chromosome number showed no significant difference among BSB, GBSB-K and GBSB-T (p > 0.05). However, the results of microsatellites (Cca15-K, Cca15-T) revealed that paternal DNA fragments were detected in GBSB-K and GBSB-T. These special DNA fragments were valuable molecular markers to distinguish gynogenetic BSB from BSB. Furthermore, the experimental results showed that GBSB-K and GBSB-T showed obviously higher hypoxia-tolerant ability than BSB (p < 0.05). Both KOC and TC were effective stimuli to induce gynogenesis of BSB and to form the "hybrid" effect. Factors including cold shock, barely living irradiated sperm and the allo-sperm "hybrid" effect potentially produce stronger gynogenetic BSB with greater hypoxia-tolerance ability. The formation of the two types of gynogenetic BSB derived from the two types of allo-sperm is of great significance in fish genetic breeding.