Due to sexual dimorphism in the growth of certain cultured fish species, the production of monosex fishes is desirable for the aquaculture industry. Nowadays, the most widely practiced technique available for the mass production of monosex fish populations is sex steroid-induced sex reversal. Here, a novel strategy for the successful production of all-female (AF) common carp (Cyprinus carpio L.), to take advantage of the sexual dimorphism in growth documented in this species, has been developed using genetic engineering via single gene-targeting manipulation without any exogenous hormone treatments. Male and female heterozygous cyp17a1-deficient common carp were first obtained using the clustered regularly interspaced short palindromic repeats/CRISPR-associated endonuclease 9 (CRISPR/Cas9) technique. An all-male phenotype for homozygous cyp17a1-deficient carp, regardless of the individuals’ sex-determination genotypes (XY or XX), has been observed. A male-specific DNA marker newly identified in our laboratory was used to screen the neomale carp population with the XX genotype from the cyp17a1-deficient carp. These neomale carp develop a normal testis structure with normal spermatogenesis and sperm capacity. The neomale common carp were then mated with wild-type (WT) females (cyp17a1^+/+ XX genotype) using artificial fertilization. All the AF offspring sample fish from the neomale-WT female mating were confirmed as having the cyp17a1^+/− XX genotype, and normal development of gonads to ovaries was observed in 100.00% of this group at eight months post-fertilization (mpf). A total of 1000 carp fingerlings, 500 from the WT male and female and 500 from the neomale and WT female mating, were mixed and reared in the same pond. The average body weight of cyp17a1^+/− XX females was higher by 6.60% (8 mpf) and 32.66% (12 mpf) than that of the control common carp. Our study demonstrates the first successful production of a monosex teleost population with the advantages of sexual dimorphism in growth using genetic manipulation targeting a single locus.

由于某些养殖鱼类生长的性别二态性，单性鱼的生产对于水产养殖业来说是可取的。如今，可用于大规模生产单性鱼种群的最广泛实践的技术是性类固醇诱导的性逆转。在这里，利用基因工程通过单基因靶向开发了一种成功生产全雌性 (AF) 鲤鱼 ( Cyprinus carpio L.) 的新策略，以利用该物种记录的生长中的两性二态性。无需任何外源性激素治疗的操作。男性和女性杂合cyp17a1-首先使用聚集的规则间隔短回文重复/CRISPR相关核酸内切酶9（CRISPR / Cas9）技术获得缺陷鲤鱼。已观察到纯合cyp17a1 缺陷鲤鱼的全雄性表型，无论个体的性别决定基因型（XY 或 XX）如何。我们实验室新发现的雄性特异性 DNA 标记用于筛选来自 cyp17a1 缺陷鲤鱼的 XX 基因型的新雄性鲤鱼种群。这些新雄性鲤鱼发育出正常的睾丸结构，具有正常的精子发生和精子能力。然后将新雄性鲤鱼与野生型 (WT) 雌性 ( cyp17a1 ^+/+XX基因型）使用人工受精。来自新雄性-WT 雌性交配的所有 AF 后代样本鱼都被确认为具有cyp17a1 ^+/- XX 基因型，并且在受精后 8 个月 (mpf) 观察到该组 100.00% 的性腺向卵巢正常发育。共有 1000 条鲤鱼鱼种，其中 500 条来自 WT 雄性和雌性，500 条来自新雄性和 WT 雌性交配，在同一个池塘中混合饲养。cyp17a1 ^+/- XX 雌性的平均体重比对照鲤鱼高 6.60% (8 mpf) 和 32.66% (12 mpf)。我们的研究表明，使用针对单个基因座的基因操作，首次成功生产出具有生长中两性二态性优势的单性硬骨鱼种群。