Exogenous thyroid hormone (TH) induces premature differentiation of the zebrafish pectoral fins, which are analogous to the forelimbs of tetrapods It accelerates the growth of the pelvic fins but not precociously Goitrogens, which are chemical inhibitors of TH synthesis by the thyroid gland, inhibit the transition from larva to juvenile fish including the formation of scales, and pigment pattern; they stunt the growth of both pectoral and pelvic paired fins Inhibition by goitrogens is rescued by the simultaneous addition of thyroxine The effect of adding TH to the rearing water of the postembryonic Mexican axolotl was reinvestigated under conditions that permit continued growth and development In addition to morphological changes that have been described, TH greatly stimulates axolotl limb growth causing the resulting larva to be proportioned as an adult in about two months This study extends the known evolutionary relatedness of tetrapod limbs and fish fins to include the TH stimulation of salamander limb and zebrafish fin growth, and suggests that TH is required to complete the life cycle of a typical bony fish and a salamander at the same developmental stage that it controls anuran and flounder metamorphosis

https://www.pnas.org/content/pnas/94/24/13011.full.pdf

The role of thyroid hormone in zebrafish and axolotl development

PART 1: INTEGRATING MECHANISMS INTO LIFE HISTORY EVOLUTION PART 2: GROWTH, DEVELOPMENT, AND MATURATION PART 3: REPRODUCTION PART 4: LIFESPAN, AGING AND SOMATIC MAINTENANCE PART 5: LIFE HISTORY PLASTICITY PART 6: LIFE HISTORY INTEGRATION AND TRADE-OFFS PART 7: CONCLUDING REMARKS

Mechanisms of Life History Evolution: The Genetics and Physiology of Life History Traits and Trade-Offs

Changes in cortisol and thyroid hormone concentrations during early development and metamorphosis in the Japanese flounder, Paralichthys olivaceus.

We have reviewed the stages in teleost thyroid function and its regulation, from the initial biosynthesis of the TH to their eventual interaction with putative receptors

Measurement and regulation of thyroidal status in teleost fish

Although fish thyroidal and reproductive systems have been researched extensively, they have been studied largely in isolation from each other. The potential for interactions between the two systems is considerable. Interactions have been suggested (Pickford and Atz, 1957; Berg et al., 1959; Ball, 1960; Matty, 1960, 1985; Dodd and Matty, 1964; Gorbman, 1969; Singh, 1970; Sage and Bern, 1971; Dodd, 1975, 1983; Donaldson and Hunter, 1983), and reviewed more extensively by Eales (1979), Nagahama (1983), Leatherland (1987, 1994), and Dickhoff et al. (1989). Sage (1973) has pointed out the structural similarities between thyroid-stimulating hormone (TSH)” and gonadotrophins and suggested some role of the thyroid in regulation of fish reproduction. Theoretically, thyroid hormones (TH) might influence any aspect of female or male reproductive function from the level of the brain to the level of receptors for gonadal steroids, and to the expression of secondary sexual characteristics (Fig. 1). By parallel reasoning, gonadal steroids and other reproductive hormones might influence any aspect of thyroid function or TH action. Our present objective is to review literature relating to the interrelationships between

Interrelationships between thyroidal and reproductive endocrine systems in fish

Analyse et comparaison des concentrations totales de triiodothyronine et de thyroxine chez P. olivaceus en fonction de ses stades de developpement primaires et de sa metamorphose. Evaluation du role de ces deux hormones dans le developpement primaire et la metamorphose

Tetsuyat Hirano

Papers

Changes in thyroid hormone concentrations during early development and metamorphosis of the flounder, Paralichthys olivaceus : Endocrinology