title: Cloning and expression analysis of tyrosine hydroxylase and changes in catecholamine levels in brain during ontogeny and after sex steroid analogues exposure in the catfish, Clarias batrachus.
abstract: Tyrosine hydroxylase (Th) is the rate-limiting enzyme for catecholamine (CA) biosynthesis and is considered to be a marker for CA-ergic neurons, which regulate the levels of gonadotropin-releasing hormone in brain and gonadotropins in the pituitary. In the present study, we cloned full-length cDNA of Th from the catfish brain and evaluated its expression pattern in the male and female brain during early development and after sex-steroid analogues treatment using quantitative real-time PCR. We measured the CA levels to compare our results on Th. Cloned Th from catfish brain is 1.591 kb, which encodes a putative protein of 458 amino acid residues and showed high homology with other teleosts. The tissue distribution of Th revealed ubiquitous expression in all the tissues analyzed with maximum expression in male and female brain. Copy number analysis showed two-fold more transcript abundance in the female brain when compared with the male brain. A differential expression pattern of Th was observed in which the mRNA levels were significantly higher in females compared with males, during early brain development. CAs, l-3,4-dihydroxyphenylalanine, dopamine, and norepinephrine levels measured using high-performance liquid chromatography with electrochemical detection in the developing male and female brain confirmed the prominence of the CA-ergic system in the female brain. Sex-steroid analogue treatment using methyltestosterone and ethinylestradiol confirmed our findings of the differential expression of Th related to CA levels.
authors: Department of Animal Sciences, School of Life Sciences - Centre for Advanced Studies, University of Hyderabad, P.O. Central University, Hyderabad 500046, Andhra Pradesh, India.
authors: Sajwan Khatri
authors: SK
authors: Mamta
authors: Department of Animal Sciences, School of Life Sciences - Centre for Advanced Studies, University of Hyderabad, P.O. Central University, Hyderabad 500046, Andhra Pradesh, India.
authors: Kavarthapu
authors: K
authors: Raghuveer
authors: Department of Animal Sciences, School of Life Sciences - Centre for Advanced Studies, University of Hyderabad, P.O. Central University, Hyderabad 500046, Andhra Pradesh, India.
authors: Cheni-Chery
authors: CC
authors: Sudhakumari
authors: Department of Animal Sciences, School of Life Sciences - Centre for Advanced Studies, University of Hyderabad, P.O. Central University, Hyderabad 500046, Andhra Pradesh, India.
authors: Anbazhagan
authors: A
authors: Rajakumar
authors: Fisheries Research and Information Centre (Inland), Karnataka Veterinary, Animal and Fisheries Sciences University, Bengaluru 560089, Karnataka, India.
authors: Yaraguntappa
authors: Y
authors: Basavaraju
authors: Department of Animal Sciences, School of Life Sciences - Centre for Advanced Studies, University of Hyderabad, P.O. Central University, Hyderabad 500046, Andhra Pradesh, India. Electronic address: bsksl@uohyd.ernet.in.
authors: Balasubramanian
authors: B
authors: Senthilkumaran
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000196:embryology* / Q000502:physiology; D002395:Catecholamines / Q000096:biosynthesis* / Q000378:metabolism; D002397:Catfishes / Q000235:genetics* / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D004298:Dopamine / Q000378:metabolism; D004997:Ethinyl Estradiol / Q000494:pharmacology; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects / Q000502:physiology; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism; D007030:Hypothalamo-Hypophyseal System / Q000196:embryology / Q000502:physiology; D007980:Levodopa / Q000378:metabolism; D008297:Male; D008777:Methyltestosterone / Q000494:pharmacology; D008969:Molecular Sequence Data; D009638:Norepinephrine / Q000378:metabolism; D010802:Phylogeny; D012333:RNA, Messenger / Q000378:metabolism; D046468:Sexual Development / Q000235:genetics* / Q000502:physiology; D014446:Tyrosine 3-Monooxygenase / Q000235:genetics* / Q000502:physiology
chemical_list: D002395:Catecholamines; D018076:DNA, Complementary; D012333:RNA, Messenger; D007987:Gonadotropin-Releasing Hormone; D004997:Ethinyl Estradiol; D007980:Levodopa; D014446:Tyrosine 3-Monooxygenase; D008777:Methyltestosterone; D004298:Dopamine; D009638:Norepinephrine
keywords: Catecholamines; Hypothalamo-hypophyseal axis; Sex differentiation; Sex steroid analogues; Teleosts; Tyrosine hydroxylase