Carotenoids and Reproduction

Abstract

Summary .After a brief discussion of the essential chemical properties of carotenoids, the identification, occurrence and distribution of the pigments in the gonads and related organs of plants and animals have been reviewed. The information available concerning the metabolism of carotenoids in reproductive tissues and their possible function in reproduction has also been reviewed systematically. In the higher plants, as maturation proceeds the carotenoid content of the tissues decreases, owing probably to the redirection of carotenoid synthesis into the reproductive organs. Further, the synthetic mechanism itself must be altered in some way because new carotenoids, never encountered in leaves, are produced in the reproductive organs. There is no evidence that carotenoids are involved in fertilization. In fact, many pollens contain no carotenoids. Differential distribution of carotenoids in male and female gametes is encountered in some species of both algae and fungi, but whereas nothing is known about carotenoid metabolism and function in relation to reproduction in fungi, it is claimed that appropriate mixtures of stable and labile crocetin dimethyl esters stimulate both male and female gametogenesis in the alga Chlamydomonas. In aquatic animals carotenoids are actively mobilized into the gonads during sexual reproductive activity, and in some cases are rendered water‐soluble by attachment to proteins. Carotenoids do not appear to be necessary for normal embryonic development, but one report indicates their possible importance as fertilization hormones. Carotenoids may be present in the gonads to ensure that the larvae are adequately equipped for chromatophore responses. Changes in general coloration associated with sexual activity are also often mediated through carotenoids; in the case of the fish Cyclopterus lumpus, for example, astaxanthin appears in the skin in large amounts during the summer spawning period. Similar changes can be observed in some insects, for instance, the bright yellow colour of sexually mature locusts is due to accumulation of β‐carotene in the cuticle. In mammals which store carotenoids, these pigments undergo metabolic changes associated with parturition, but as not all mammals store carotenoids, and since many similar changes occur with vitamin A, it is doubtful whether the carotenoids are of significance per se. Although carotenoids appear to be unnecessary for the normal development of birds in both the pre‐ and post‐embryonic stages, they are actively mobilized into birds' eggs. They may, however, be necessary for optimum conditions of fertilization by increasing the sperm competitive ability of cocks, i.e. when hens are inseminated with an equal mixture of spermatozoa from cocks on an adequate diet and those on a lutein‐deficient diet, a larger proportion of offspring are produced from the normal group than from the lutein‐deficient group.

Biochemical composition of ovary, embryo, and hepatopancreas in the grapsoid crabs Armases cinereum and Sesarma nr. reticulatum (Crustacea, Decapoda)

“…The color of the hepatopancreas may fluctuate in wild caught crabs because of the presence of carotenoids in the diet and how these pigments are metabolized. In some crustaceans carotenoids are mobilized from the hepatopancreas to the gonad (Goodwin, 1950).…”

The proximate basis of inter- and intra-population variation in female plumage coloration in the House Finch

“…It is well known that birds cannot synthesize carotenoid pigments and must obtain them from their diet (Goodwin 1950;Brush 1978Brush , 1990. It has previously been shown that variation in male House Finch coloration both within (Brush and Power 1976;Hill 1992) and among populations (Hill 19936) is a consequence of individual variation in the intake of carotenoid pigments rather than intrinsic differences among individuals in the ability to display coloration.…”

Effects of dietary astaxanthin supplementation on reproductive characteristics of rainbow trout (Oncorhynchus mykiss)

“…Thus, during oogenesis, carotenoids are mobilized from the muscle, incorporated into the growing ovary, and found in the unesterified form in the mature eggs (Steven, 1949; Kitahara, 1983, 1984). Due to their accumulation in reproductive organs of many types of organisms, carotenoids have for a long time been expected to play a role in reproductive processes (Goodwin, 1950).…”