The direction of genital asymmetry is expressed stochastically in internally fertilizing anablepid fishes
The direction of genital asymmetry is expressed stochastically in internally fertilizing anablepid fishes
复制标题
生殖器不对称的方向在体内受精的无能鱼类中随机表达
DOI：
10.1098/rspb.2020.0969
复制
发表时间：
1930
期刊：
影响因子：
--
通讯作者：
Aguilera
中科院分区：
文献类型：
--
作者：
Torres-Dowdall;Rometsch;Aguilera
动物的外生殖器在不同的分类群之间有很大的差异，在许多形态特征上存在分歧，包括明显偏离对称性。人们提出了不同的机制来解释这种多样性，大多假设至少有一些表型变异是可遗传的。然而，生殖器不对称方向的遗传性很少被确定。Anablepidae是一种体内寄生的鱼类，雄性的臀鳍已经被改造成一个能将精子转移到雌性生殖孔的内分泌器官。雄性拟步鱼的外生殖器不对称，左侧和右侧的个体在种群中的比例相似（即反对称）。尽管这种多态性在世纪前就被描述过，但还没有人试图确定生殖器不对称是否有遗传基础，以及不同的变体是否积累了遗传差异，因为在某些物种中，雌性也有不对称的生殖孔，因此只能由相容的不对称雄性受精。我们解决这个问题相结合的育种实验与全基因组数据（ddRAD标记）在两个anablepid属的代表性物种与不对称的生殖器：AnablepsandJenynsia。育种实验表明，所有的后代是不对称的，但他们的形态（即右侧或左侧）是独立的父母形态，这意味着不对称的方向没有很强的遗传成分。与这一结论相一致，基于约25 000个SNP的关联分析没有发现与生殖器不对称方向显著相关的标记，也没有证据表明左侧和右侧个体之间存在群体结构。这些结果表明，在anablepid鱼类的生殖器不对称的方向可能是随机的，一个常见的模式，在形态特征的反对称物种。
Animal genitalia vary considerably across taxa, with divergence in many morphological traits, including striking departures from symmetry. Different mechanisms have been proposed to explain this diversity, mostly assuming that at least some of the phenotypic variation is heritable. However, heritability of the direction of genital asymmetry has been rarely determined. Anablepidae are internally fertilizing fish where the anal fin of males has been modified into an intromittent organ that transfers sperm into the gonopore of females. Males of anablepid fishes exhibit asymmetric genitalia, and both left- and right-sided individuals are commonly found at similar proportions within populations (i.e. antisymmetry). Although this polymorphism was described over a century ago, there have been no attempts to determine if genital asymmetry has a genetic basis and whether the different morphs are accumulating genetic differences, as might be expected since in some species females have also asymmetric gonopores and thereby can only be fertilized by compatible asymmetric males. We address this issue by combining breeding experiments with genome-wide data (ddRAD markers) in representative species of the two anablepid genera with asymmetric genitalia:AnablepsandJenynsia. Breeding experiments showed that all offspring were asymmetric, but their morphotype (i.e. right- or left-sided) was independent of parental morphotype, implying that the direction of asymmetry does not have a strong genetic component. Consistent with this conclusion, association analyses based on approximately 25 000 SNPs did not identify markers significantly associated with the direction of genital asymmetry and there was no evidence of population structure between left- and right-sided individuals. These results suggest that the direction of genital asymmetry in anablepid fishes might be stochastic, a commonly observed pattern in species with antisymmetry in morphological traits.
登录
查看更多内容
鲤科鱼类（Teleostei、Atherinomorpha）的系统发育和生物地理学分析
DOI：
--
发表时间：
1981
期刊：
影响因子：
--
作者：
L. Parenti
通讯作者：
L. Parenti
生殖器的不对称与侧化交配行为同步，但与其他行为的侧化不同步
影响因子：
2.2
作者：
Torres-Dowdall;Rometsch;Aguilera;Goyenola
通讯作者：
Goyenola
机械感受器和最小反射活动决定龙虾发育中的爪侧向性
DOI：
--
发表时间：
1992
期刊：
影响因子：
--
作者：
C. Govind;J. Pearce
通讯作者：
J. Pearce
DOI：
--
发表时间：
2000
期刊：
影响因子：
--
作者：
R. Shine;M. Olsson;M. Lemaster;I. Moore;R. Mason
通讯作者：
R. Mason
影响因子：
4.9
作者：
Franchini, Paolo;Parera, Daniel Monne;Meyer, Axel
通讯作者：
Meyer, Axel