Abstract
The spermatozoa of triploid gynogenetic crucian carp (Carassius auratus) (3nDTCC) possess a spermatogenesis process with a normal genetic background. However, the genetic materials of these spermatozoa do not completely inherit gynogenetic progeny in general. Understanding the intrinsic mechanism may be helpful for developing breeding strategies of gynogenetic fishes. In this study, the spermatozoa ultrastructure was systematically studied in diploid red crucian carp and 3nDTCC to demonstrate their cytological structural differences. In addition, the artificial breeding tests of 3nDTCC(♀) with different ploidy spermatozoa were performed to verify the contributions of genetic materials from 3nDTCC spermatozoa to the gynogenesis progeny. Furthermore, the mRNA expression of centriole-related genes (i.e., cep57, cetn1, rootletin, and nek2) involved in spermatozoa packaging was also determined by quantitative real-time PCR (qPCR) to illustrate the molecular expression characteristics of the spermatozoa packaging process in 3nDTCC. The results reveal the adaptive features of spermatozoa in 3nDTCC, including the loose midpiece structure, abnormal head structure, and abnormal expression of centriole-related genes, which may influence the motility of spermatozoa and make it not involved normally in the genetic composition of the gynogenesis offspring.
Highlights
Crucian carp (Carassius auratus L.,), which belongs to the genus of Carassius within the family of Cyprinidae, has a wide geographic distribution in the Eurasian continent
The mRNA expression of centriole-related genes which were involved in spermatozoa packaging was determined by quantitative real-time PCR to illustrate the molecular mechanism of the abnormal spermatozoa packaging process in 3nDTCC
The introgression of paternal DNA might play an important role in the creation of genetic diversity in gynogenetic fish, for example, extra microchromosomes in males are closely related to male determination in gynogenetic gibel carp (Li et al, 2016; Zhao et al, 2021; Ding et al, 2021), and the insertion of paternal DNA was reported in gynogenetic blunt snout bream (Gong et al, 2019)
Summary
Crucian carp (Carassius auratus L.,), which belongs to the genus of Carassius within the family of Cyprinidae, has a wide geographic distribution in the Eurasian continent. Carassius auratus gibelio (C. gibelio Bloch) is originated from sympatric progenitor crucian carp (Carassius auratus) (Li et al, 2014), which is widely distributed in the Heilongjiang water system and many other natural habitats (Sheng and Wang, 1983; Gui and Zhou, 2010; Zhou et al, 2000). Most crucian carp in the abovementioned different natural waters have two sex ratio groups—bisexual and unisexual. The former always possesses a certain proportion of males, which can reproduce and undergo normal bisexual fertilization.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
