Karyotyping and Molecular Sexing in Brycinus nurse (Characiformes, Alestidae) from Nile River in Egypt

Abstract

The present study aimed to investigate the karyotype and molecular sex differences in Brycinus nurse. Analysis of 430 metaphases spreads from 12 specimens revealed that the diploid chromosome number is 44 chromosomes and the proposed karyotype formula is n = 3 M + 3 SM + 16 A, FN = 56. No morphologically differentiated heteromorphic sex chromosomes were observed. On the other hand, 29 primers of three molecular markers (RAPD, SCoT and ISSR) were tested to differentiate between males and females of B. nurse. From all tested primers only two primers (OPI-18 and SCoT-18) successfully generated female specific bands in the bulked DNA samples which further confirmed using individual DNA samples. According to molecular analysis result in this study it seems that females of B. nurse are the heterogametic gender (ZW) and males of B. nurse are the homogametic gender (ZZ). In the future, SCoT marker can be used as suitable and powerful marker in genetic analysis studies in fish.

First cytogenetic data on Afrotropical lutefishes (Citharinidae) in the light of karyotype evolution in Characiformes

“…In contrast to Crenuchidae, two groups of other Characoidei families stem out rather close to the basal nodes but the karyotype structures of most of their members that were cytogenetically studied are enriched with or even dominated by uni-armed chromosomes. The first group consists of Neotropical Ctenoluciidae and Lebiasinidae, while the second group comprises Afrotropical Hepsetidae and Alestidae, as well as Neotropical Erythrinidae (Arai 2011; Cioffi et al 2012;Krysanov and Golubtsov 2014;Arcila et al 2017;Carvalho et al 2017;Mohamed et al 2019). The reported exceptions in these groups are genera Hoplerythrinus Gill, 1896 and Hoplias Gill, 1903 (Erythrinidae) whose karyotypes are almost completely dominated by bi-armed chromosomes (Arai 2011; Cioffi et al 2012).…”

“…There is no cytogenetic information about any citharinid species, whereas the karyotype of the only distichodontid species, Distichodus affinis Günther, 1873, was analyzed by Rab et al (1998). In contrast, the extensive literature on the cytogenetics of Characoidei, both Afrotropical (Post 1965;Hinegardner and Rosen 1972;Krysanov and Golubtsov 2014;Carvalho et al 2017;Mohamed et al 2019) and Neotropical (reviewed by Oliveira et al 1988Oliveira et al , 2007Oliveira et al , 2009Galetti et al 1994;Fenocchio et al 2003;Nirchio et al 2014;Pazian et al 2018, Sassi et al 2020, demonstrates the substantial variety of the karyotype structure and different modes of its evolution in hundreds of cytogenetically studied species.…”

Identification of Sex-specific Molecular Markers in Barbel and Nile Carp using SCoT and ISSR Markers

“…However, it was also used to assess genetic diversity in animals such as camel (Al-Soudy et al, 2018) and fish (Marie and Allam, 2017). Also, SCoT marker was efficient to identify molecular sex marker in date palm (Adawy et al 2014 andSami 2015) and when used with fish it successfully discriminated between male and female of Brycinus nurse using bulked and individual samples (Mohamed et al 2019).…”

“…Interestingly, in the last decades, many molecular markers have been developed and successfully used in molecular sexing studies in many species including fish, such as random amplified polymorphic DNA (RAPD) (Wuertz et al, 2006;Chen et al, 2009;Durna, 2009;Xia et al, 2011;Silva et al, 2012;Al-Qurainy et al, 2018 andMohamed et al 2019), start codon targeted (SCoT) polymorphism Sami, 2015 andMohamed et al 2019) and inter simple sequence repeat (ISSR) (Wuertz et al, 2006;Adhikari et al, 2014 andMohamed et al 2019).…”