Michalik O, Dobosz S, Zalewski T, Sapota M, Ocalewicz K
Department of Molecular Evolution, University of Gdansk, Gdansk, Poland.
Department of Salmonid Research, Inland Fisheries Institute in Olsztyn, Rutki, Zukowo, Poland.
Reprod Domest Anim. 2015 Apr;50(2):256-262. doi: 10.1111/rda.12480. Epub 2015 Jan 20.
Gynogenetic and androgenetic brown trout (Salmo trutta Linnaeus 1758) haploids (Hs) and doubled haploids (DHs) were produced in the present research. Haploid development was induced by radiation-induced genetic inactivation of spermatozoa (gynogenesis) or eggs (androgenesis) before insemination. To provide DHs, gynogenetic and androgenetic haploid zygotes were subjected to the high pressure shock to suppress the first mitotic cleavage. Among haploids, gynogenetic embryos were showing lower mortality when compared to the androgenetic embryos; however, most of them die before the first feeding stage. Gynogenetic doubled haploids provided in the course of the brown trout eggs activation performed by homologous and heterologous sperm (rainbow trout) were developing equally showing hatching rates of 14.76 ± 2.4% and 16.14 ± 2.90% and the survival rates at the first feeding stage of 10.48 ± 3.48% and 12.78 ± 2.18%, respectively. Significantly, lower survival rate was observed among androgenetic progenies from the diploid groups with only few specimens that survived to the first feeding stage. Cytogenetic survey showed that among embryos from the diploid variants of the research, only gynogenetic individuals possessed doubled sets of chromosomes. Thus, it is reasonable to assume that radiation employed for the genetic inactivation of the brown trout eggs misaligned mechanism responsible for the cell divisions and might have delayed or even arrested the first mitotic cleavage in the androgenetic brown trout zygotes. Moreover, protocol for the radiation-induced inactivation of the paternal and maternal genome should be adjusted as some of the cytogenetically surveyed gynogenetic and androgenetic embryos exhibited fragments of the irradiated chromosomes.
在本研究中，产生了雌核发育和雄核发育的褐鳟（Salmo trutta Linnaeus 1758）单倍体（Hs）和加倍单倍体（DHs）。单倍体发育是通过在授精前对精子（雌核发育）或卵子（雄核发育）进行辐射诱导的遗传失活来诱导的。为了获得加倍单倍体，对雌核发育和雄核发育的单倍体合子进行高压休克以抑制第一次有丝分裂。在单倍体中，与雄核发育的胚胎相比，雌核发育的胚胎死亡率较低；然而，它们中的大多数在第一次摄食阶段之前死亡。通过同源和异源精子（虹鳟）对褐鳟卵进行激活过程中产生的雌核发育加倍单倍体发育情况相同，孵化率分别为14.76±2.4%和16.14±2.90%，在第一次摄食阶段的存活率分别为10.48±3.48%和12.78±2.18%。值得注意的是，在二倍体组的雄核发育后代中观察到显著较低的存活率，只有少数个体存活到第一次摄食阶段。细胞遗传学调查表明，在本研究的二倍体变体的胚胎中，只有雌核发育的个体拥有加倍的染色体组。因此，可以合理地假设，用于褐鳟卵遗传失活的辐射使负责细胞分裂的机制失调，可能延迟甚至阻止了雄核发育的褐鳟合子中的第一次有丝分裂。此外，由于一些经细胞遗传学调查的雌核发育和雄核发育胚胎显示出受辐射染色体的片段，应调整辐射诱导父本和母本基因组失活的方案。
