Production of inbred larvae through self-fertilization using oocytes and cryopreserved sperm from the same individuals after sex reversal in eastern oysterCrassostrea virginica

Abstract

The eastern oyster Crassostrea virginica can change sex which makes self‐fertilization possible if sperm can be cryopreserved. In this study, small (~1 year old) and large (~2–3 years old) oysters were biopsied for sperm collection. Survival of the biopsied oysters after 1 year was 50% for small oysters and 17% for large oysters. Oocytes were collected from sex‐reversed females, and self‐fertilized with cryopreserved sperm. Of the 24 cryopreserved samples, 14 individuals had ≤1% fertility when crossed with oocytes from unrelated females, indicating that the cryopreserved sperm had reduced fertility. The other 10 individuals had a fertility of 39 ± 25% when crossed with oocytes from unrelated females (non‐selfing), but showed a significantly lower success of self‐fertilization (12 ± 16%) (P = 0.008), while aliquots of the same oocytes had a fertilization of 83 ± 11% when crossing with fresh sperm. Larvae were produced at day 3 in the self‐fertilized families (12–94% of the fertilized oocytes), and survived to eyed‐larvae stage at days 11–14. Genotyping with 9 microsatellite markers confirmed that the larvae resulted from self‐fertilization in four families. This study demonstrated the feasibility of creating self‐fertilized inbred lines of oysters by use of non‐lethal sperm collection and cryopreservation.

Morphogenetic and population structure of two species marine bivalve (Ostreidae: Saccostrea cucullata and Crassostrea iredalei) in Aceh, Indonesia

“…According to Wang et al (2004), oysters are born as males until they are able to release sperm, then they will turn into females if environmental condition is suitable (Galtsoff 1964). During this male phase, the oysters focus their growth on the elongation of the shell and sperm production, before lately turn into female oysters (Yang et al 2014). When a male oyster turns into a female, the oyster will focus its growth on gaining the body weight.…”

Toward Genome-Based Selection in Asian Seabass: What Can We Learn From Other Food Fishes and Farm Animals?

“…fertilized with the frozen sperm collected earlier from the same individual as it was done in Eastern oyster (Yang et al, 2015) and shortnose sturgeon (Henne et al, 2006). Such "near-isogenic" lines produced from genetically distinct parents can later be used to create intraspecific hybrid lines that would likely yield wellperforming offspring groups suitable for commercial purposes.…”

Concepts, History, Principles, and Application of Germplasm Cryopreservation Technology

“…For shellfish, germplasm cryopreservation has been investigated in sperm, oocytes, embryos, and larvae (Yang 2017;Simon and Yang 2018). It is evident that germplasm cryopreservation has a promising future application in breeding, conservation, establishment of self-fertilization lines (Yang et al 2015), and commercial hybridization (Hu et al 2011). One of the leading germplasm repositories in the world for fishes is housed at the Zebrafish International Resource Center at the University of Oregon in Eugene (https://zebrafish.org/ home/guide.php).…”