Parnes S, Khalaila I, Hulata G, Sagi A
Department of Life Sciences and The Institute for Applied Biosciences, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva 84105, Israel.
Genet Res. 2003 Oct;82(2):107-16. doi: 10.1017/s0016672303006372.
In the Australian red-claw crayfish Cherax quadricarinatus (von Martens) (Decapoda, Parastacidae), a gonochoristic species, seven different combinations of intersex individuals (with both male and female genital openings) have been described. However, to date, the genetic basis for this phenomenon has not been investigated. This study was designed to test a simple chromosome-based sex-determination model for C. quadricarinatus that assumes the male to be the homogametic (ZZ) sex. According to our model, intersex individuals that are functionally males are genetically females (WZ). Individual crosses were performed between intersex and female crayfish, with control crosses being performed between normal males and females. The control crosses yielded, in most cases, the expected 1:1 sex ratio in the F1 progeny. Crosses between intersex individuals and females yielded a 1:3 (male:female) sex ratio in most crosses. According to our hypothesis, one-third of the females produced in a cross of a female with an intersex animal should be WW females. The hypothesis was tested by crossing normal males with F1 females, which were progeny of intersex fathers. These crosses yielded almost 100% females, a finding that conforms to the above-suggested sex determination model for C. quadricarinatus and the female WZ genotype of intersex individuals.
在澳大利亚红爪螯虾四脊光壳螯虾（Cherax quadricarinatus，冯·马滕斯）（十足目，拟螯虾科）中，这是一种雌雄异体的物种，已描述了七种不同的雌雄同体个体组合（同时具有雄性和雌性生殖孔）。然而，迄今为止，尚未对这一现象的遗传基础进行研究。本研究旨在测试一种针对四脊光壳螯虾的基于染色体的简单性别决定模型，该模型假设雄性为同配性别（ZZ）。根据我们的模型，功能上为雄性的雌雄同体个体在基因上是雌性（WZ）。在雌雄同体和雌性螯虾之间进行了个体杂交，并在正常雄性和雌性之间进行了对照杂交。在大多数情况下，对照杂交在F1后代中产生了预期的1:1性别比。雌雄同体个体与雌性之间的杂交在大多数杂交中产生了1:3（雄性:雌性）性别比。根据我们的假设，雌性与雌雄同体动物杂交产生的雌性后代中三分之一应为WW雌性。通过将正常雄性与F1雌性杂交来检验这一假设，F1雌性是雌雄同体雄性的后代。这些杂交产生了几乎100%的雌性，这一结果符合上述提出的四脊光壳螯虾性别决定模型以及雌雄同体个体的雌性WZ基因型。
