High corticosterone and sex reversal in common carp (Cyprinus carpio L.) with adrenal hyperplasia caused by P450c17a2 deficiency
Nematollahi, M.A. ; Pelt-Heerschap, H.M.L. van; Komen, H. - \ 2014
Aquaculture 418-419 (2014). - ISSN 0044-8486 - p. 165 - 170.
teleost fish - 21-hydroxylase deficiency - interrenal hyperplasia - recessive mutation - cortisol response - determining gene - oryzias-latipes - stress-response - rainbow-trout - expression
The aim of this study was to investigate the inheritance of adrenal hyperplasia, caused by 17a-hydroxylase deficiency, and its association with female to male sex reversal in common carp. Inbred strains used in this experiment were E4 (XX, female, normal), E5 (XX, male, adrenal hyperplasia) and E7 (XX, male, adrenal hyperplasia). F1 females (E4E5: XX, normal) were crossed to E5 and E7 males to produce backcross progeny (BC5 and BC7), or reproduced by gynogenesis to produce doubled haploid progeny (DH). Fish (age 6 months) were subjected to a net confinement stressor and sacrificed to collect blood plasma for analysis of cortisol and corticosterone, and to determine sex. Values for plasma corticosterone showed a clear segregation pattern, consistent with a single recessive gene model. There was a highly significant difference between high and low corticosterone responders in BC and DH progeny groups. Mean corticosterone values for high corticosterone responders in the three groups BC5, BC7 and DH were, respectively: 1706, 1760 and 1366 ng/ml. For low corticosterone responders values were 1.5, 1.1 and 0.6 ng/ml. High corticosterone responders had on average low levels of cortisol: 21.3, 24 and 17.3 ng/ml for BC5, BC7 and DH. Low corticosterone responders had normal levels (66.7, 105.1 and 65.2 ng/ml for BC5, BC7 and DH, respectively). Sex ratios were significantly different between high and low corticosterone responders. High corticosterone responders were predominantly male, while low corticosterone responders were female or intersex. High corticosterone responders had well developed testis and were fertile indicating that in the gonads, 17a-hydroxylase is not impaired. The observed effect on sex shows that 17a-hydroxylase deficiency most likely augments sex reversal in common carp, either directly through high levels of plasma corticosterone, or through paracrine effects of elevated ACTH production.
Stress-induced facilitation of the cortisol response in 17a-hydroxylase deficient XX mas -1/mas -1 carp (Cyprinus carpio)
Ruane, N.M. ; Goos, H.J.Th. ; Komen, J. - \ 2007
General and Comparative Endocrinology 150 (2007)3. - ISSN 0016-6480 - p. 473 - 479.
pituitary-interrenal axis - common carp - rainbow-trout - recessive mutation - adrenal axis - food-intake - fish - growth - adrenocorticotropin - hyperplasia
Facilitation of the stress response results from a reduction of the inhibitory effects of circulating corticosteroids, allowing an animal to respond to a novel stressor. In this study, the existence of a facilitated cortisol stress response in normal (STD) and 17¿-hydroxylase deficient XX mas¿1/mas¿1 (E5) carp was investigated. E5 carp had previously been characterized as having a low cortisol response to stress. Fish were subjected to either cortisol feeding or daily-acute stress, from 45 until 140 days post-hatch (dph) and were then subjected to a novel net-confinement stressor at 141 dph. Growth of E5 fish was reduced in both the daily-acute stress and cortisol-fed groups, but STD fish were only affected by daily-acute stress. Cortisol feeding had no effect on the stress response of STD fish but daily-acute stress significantly inhibited the response to a subsequent novel stressor. In contrast, daily-acute stress facilitated the cortisol stress response of E5 fish to a novel stressor, while cortisol feeding inhibited the cortisol response. Facilitation was accompanied by significant enlargement of the head-kidney tissue (which contains the steroidogenic interrenal tissue) in E5 fish. To our knowledge this is the first report of stress-induced facilitation in a lower vertebrate
Hypocorticism and interrenal hyperplasia are not directly related to masculinization in XXmas(-1)/mas(-1) carp, Cyprinus carpio
Ruane, N.M. ; Lambert, J.G.D. ; Goos, H.J.Th. ; Komen, J. - \ 2005
General and Comparative Endocrinology 143 (2005)1. - ISSN 0016-6480 - p. 66 - 74.
congenital adrenal-hyperplasia - common carp - recessive mutation - stress-response - rainbow-trout - cortisol - hormone - fish - differentiation - localization
This study reports on a homozygous XX male strain of common carp (E5), which fail to mount a normal cortisol stress response. Earlier classical genetic analysis had indicated that masculinization of E5 fish was caused by a putative recessive mutation (mas¿1/mas¿1). Hypocorticism in E5 fish was studied to investigate if it was related to masculinization. Head-kidney tissues isolated from E5 fish showed a low cortisol-producing capacity in vitro, and also demonstrated a reduced sensitivity to stimulation with ACTH, when compared with an isogenic XY male carp strain (STD). There was no strain difference in androgen production by head-kidney tissues in vitro. E5 fish exhibited significant hyperplasia of the interrenal tissue (adrenal homologue of teleost fish) located in the head-kidney. Conversion of pregnenolone was significantly lower in E5 head-kidney homogenates, compared to STD homogenates, however, no strain difference was found in the conversion of 17¿-hydroxyprogesterone into cortisol. Gonad homogenates incubated with pregnenolone showed no strain difference in conversion to corticosteroids and androgens. Results indicate that the interrenal hyperplasia and hypocorticism in this strain of carp may be due to a dysfunction of the 17¿-hydroxylase activity of the enzyme P450c17 in the interrenal, but that this defect may not be the primary factor resulting in masculinization of these XX genotypes