The obvious heterosis and genetic characters of intergeneric cross and backcross juveniles between blunt snout bream ( Megalobrama amblycephala ) and topmouth culter ( Culter alburnus )

Abstract

In this study, we used artificial insemination to generate hybrid groups of fish [MC‐F1(MA♀×CA♂) and MC‐F2(MC‐F1♀×♂)] by intergeneric crosses of Megalobrama amblycephala (MA) and Culter alburnus (CA); sequential backcrosses [CAM‐B1 (CA♀×MC‐F1♂) and MCC‐B1 (MC‐F1♀×CA♂)] were also performed. All these hybrids showed high rates of fertilization, hatching and survival (p > 0.05). For genetic traits, compared with those of the M. amblycephala and C. alburnus parental lines (Table 1), the fertilization rate, hatching rate and 7‐day survival rate of MC‐F1(MA♀×CA♂), MC‐F2(MC‐F1♀×♂), CAM‐B1 (CA♀×MC‐F1♂) and MCC‐B1 (MC‐F1♀×CA♂) by artificial insemination exhibited similar high rates (p > 0.05). The morphology of the four hybrids MC‐F1/F2, CAM‐B1 and MCC‐B1 were intermediate between those of their parents. Compared with their parents of MA and CA, weight gain rate (WG), specific growth rate (SGR) and protein efficiency ratio (PER) of hybrids MC‐F1/F2, CAM‐B1 and MCC‐B1 were significantly (p < 0.05) increased and feed conversion ratio (FCR) was significantly (p < 0.05) decreased after 3 months feeding. Moreover, protein content of muscle for MC‐F1/F2, CAM‐B1 and MCC‐B1 was significantly (p < 0.05) higher and carbohydrate content of muscle was significantly (p < 0.05) lower than their parents. The females and males of the four hybrids had normal gonadal development. In this study, we successfully generated intergeneric and backcross hybridization lines with fertile potential among fish of the Cultrinae subfamily and these hybrids had obvious heterosis in terms of growth performance, feed utilization and muscle quality.

De novo transcriptome analysis reveals possible heterosis for growth, immunity and anti‐oxidation of Macrobrachium nipponense hybrid offspring and parent populations

“…The other is represented by the incompatible interaction between the two parents, an interaction that appears to have a weakening effect on the growth‐limiting process in hybrids (Herbst et al, 2017). However, heterosis involves molecular changes at different levels of genetic, epigenetic, proteomic and metabolomic regulatory networks (Luo et al, 2014; Guo et al, 2019).…”

Optimal dietary protein requirement of juvenile backcross variety,Megalobrama amblycephala♀ × (M. amblycephala♀ ×Culter alburnus♂) ♂

“…For instance, the hybrids between M. amblycephala and C. alburnus were found to be fertile (Xiao et al., 2014). This hybrid was also found to exhibit reduced intermuscular bone count compared with that their male parent (Wu et al., 2020) and improved muscle quality (Zheng, Guo, et al, 2019). Moreover, the levels of total and essential amino acid of this hybrids were superior to those of their parents (He et al, 2014).…”

Establishment and identification of the gill cell line from the blunt snout bream (Megalobrama amblycephala) and its application in studying gill remodeling under hypoxia

“…Blunt snout bream (Megalobrama amblycephala) commonly known as the Wuchang sh, is one of China's primary freshwater herbivorous sh species (Shuang et al 2023). However, compared to lowoxygen-tolerant sh such as carp and crucian carp, blunt snout bream is more prone to hypoxia-induced mortality in large-scale aquaculture, which impedes yield enhancement (Zheng et al 2019). Research on the causes of hypoxia in sh has con rmed the prevalence of gill remodeling in most species, such as gold sh (Jin et al 2018), crucian carp (Jørund et al 2005), and Chen et al (2023) veri ed the phenomenon of gill remodeling on the gill structure of blunt snout bream.…”