Aclonal Reproduction by Polyploid Members of the Clonal Hybrid Species Phoxinus eos-neogaeus (Cyprinidae)
Aclonal Reproduction by Polyploid Members of the Clonal Hybrid Species Phoxinus eos-neogaeus (Cyprinidae)
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克隆杂交种 Phoxinus eos-neogaeus（鲤科）的多倍体成员的无性繁殖
DOI：
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发表时间：
1993
期刊：
影响因子：
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通讯作者：
R. Schultz
中科院分区：
文献类型：
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作者：
K. Goddard;R. Schultz
杂交的镖水蚤Phoxinus eos和P. neogaeus出现在整个北方美国和加拿大南部。来自新罕布什尔州库斯县East Inlet Pond的二倍体杂种和一些二倍体-三倍体镶嵌杂种产生了二倍体全相同的原始对虾卵子，如果来自任何一个亲本物种的精子仅用于刺激发育，则这些卵子发育成二倍体幼鱼，但如果精子基因组实际上已整合，则发育成三倍体或二倍体-三倍体镶嵌幼鱼。东入口池塘的杂交种群似乎通过这种独特的精子依赖性克隆繁殖形式得以延续。在这里，我们报告两个额外的形式的繁殖的基础上，从东入口池塘，新罕布什尔州收集的两个马赛克和两个三倍体杂交雌性实验室产卵。这两个三倍体产生的二倍体后代在几个外部形态特征的基础上与P. eos无法区分。此外，后代在所有六个诊断位点上都具有P.eos的等位酶特征，并且它们具有组织相容性抗原和其母亲缺失的Gpi-B等位基因。相反，它们的消化道卷曲的形态特征之间的P.neogaeus和P.eos。总的来说，这些数据表明，三倍体雌性产生的单倍体卵子只含有或大部分含有P.eos的染色体，这些卵子被P.eos的精子受精。这两个嵌合体产生的后代携带P. eosneogaeus的克隆基因组，表明它们产生的P. eos-neogaeus的二倍体全相同的卵子与我们以前报道的二倍体和嵌合体杂种一样。然而，他们也产生了一些不携带克隆基因组的后代，显然来自未知倍性水平的不相同卵子。本文报道的三倍体和嵌合体杂种的繁殖可能会给杂种群体带来更大的变异。这些繁殖模式也可能提供了一种载体，通过这种载体，基因可以在亲本物种P.eos和P.neogaeus之间交换。
Hybrids of the daces Phoxinus eos and P. neogaeus occur throughout the northern United States and southern Canada. Diploid hybrids and some diploid-triploid mosaic hybrids from East Inlet Pond, Coos County, New Hampshire, produce diploid all-identical ova of P. eos-neogaeus that develop into diploid young if sperm from either parental species serves only to stimulate development but triploid or diploid-triploid mosaic young if the sperm genome is actually incorporated. The hybrid population at East Inlet Pond appears to be perpetuated by this unique form of sperm-dependent, clonal reproduction. Here we report two additional forms of reproduction based on laboratory spawnings of two mosaic and two triploid hybrid females collected from East Inlet Pond, New Hampshire. The two triploids produced diploid offspring that were indistinguishable from P. eos on the basis of several external morphological traits. In addition, the offspring possessed allozymes characteristic of P. eos at all six diagnostic loci tested, and they had histocompatibility antigens and an allele of Gpi-B absent from their mothers. Conversely, the coiling of their digestive tracts varied between the morphology characteristic of P. neogaeus and that of P. eos. Collectively, these data suggest that the triploid females produced haploid ova containing exclusively or mostly chromosomes of P. eos that were fertilized by sperm of P. eos. The two mosaics produced offspring that carried the clonal genome of P. eosneogaeus, indicating that they produced diploid all-identical ova of P. eos-neogaeus like the diploid and mosaic hybrids we have previously reported. However, they also produced some offspring that did not carry the clonal genome, apparently from nonidentical ova of unknown ploidy level. Reproduction by the types of triploid and mosaic hybrids reported here may introduce greater variation into hybrid populations. These modes of reproduction may also provide a vehicle by which genes may be exchanged between the parental species, P. eos and P. neogaeus.