scholarly journals Telomere dynamics from hatching to sexual maturity and maternal effects in the ‘multivariate egg’

2020 ◽  
Vol 223 (23) ◽  
pp. jeb232496 ◽  
Author(s):  
Francois Criscuolo ◽  
Roxanna Torres ◽  
Sandrine Zahn ◽  
Tony D. Williams

ABSTRACTAvian eggs contain a large number of molecules deposited by the mother that provide the embryo with energy but also potentially influence its development via the effects of maternally derived hormones and antibodies: the avian egg is thus ‘multivariate’. Multivariate effects on offspring phenotype were evaluated in a study on captive zebra finches, by simultaneously manipulating maternally derived antibodies (MAb) by lipopolysaccharide (LPS) treatment of mothers and injection of testosterone into the egg yolk. LPS treatment had a positive effect on body mass growth at 30 days after hatching and immune response at sexual maturity, while egg testosterone treatment positively influenced immune response at fledging and courtship behaviour in sexually mature male offspring. Maternal effects are known to modulate offspring telomere length (TL). However, the multivariate effects of egg-derived maternal components on offspring telomere dynamics from hatching to sexual maturity are undefined. Here, we tested: (1) the effects of LPS and testosterone treatments on TL from hatching to sexual maturity (day 82); (2) how LPS treatment modulated TL over reproduction in adult females; and (3) the relationship between maternal and offspring TL. We predicted that TL would be shorter in LPS fledglings (as a cost of faster growth) and that TL would be longer in sexually mature adults after yolk testosterone treatment (as a proxy of individual quality). In adult females, there was an overall negative relationship between laying and rearing investments and TL, this relationship was weaker in LPS-treated females. In chicks, there was an overall negative effect of LPS treatment on TL measured at fledging and sexual maturity (day 25–82). In addition, at fledging, there was a Sex×LPS×Testosterone interaction, suggesting the existence of antagonistic effects of our treatments. Our data partially support the hypothesis that telomeres are proxies of individual quality and that individual differences in TL are established very early in life.

1964 ◽  
Vol 45 (1) ◽  
pp. 1-12 ◽  
Author(s):  
H. E. Swanson ◽  
J. J. van der Werff ten Bosch

ABSTRACT The »early-androgen« syndrome in the rat – i. e. anovulatory ovaries in adult females after a single injection of testosterone propionate (TP) within a week of birth – may not become apparent until some time after the attainment of sexual maturity. Large doses (50 or 100 μg) of TP were effective earlier than lower doses (5 or 10 μg). Rats which received 5 μg TP were ovulating at 10 weeks of age, mated but were infertile at 13 weeks of age, and were anovulatory at 21 weeks. In rats between 10 and 13 weeks old there was a marked fall in the number of corpora lutea in the ovaries of animals which had been given 5 μg TP. Hemi-spaying was followed by compensatory growth of the remaining ovary which consisted of corpora lutea in ovulating, and of follicles in anovulatory rats; little or no compensatory weight increase occurred in animals which seemed to be in the transition stage from the ovulatory to the anovulatory condition.


1979 ◽  
Vol 13 (3) ◽  
pp. 283-286 ◽  
Author(s):  
M. L. Norris ◽  
C. E. Adams

Summary Keeping a sexually mature male with a weanling female rat advanced neither the time of vaginal opening nor that of 1st oestrus. In 2 of 3 experiments females kept singly after weaning reached sexual maturity significantly earlier than did grouped females. The reproductive performance of females mated at 1st oestrus was not significantly different from that of older primiparae. 26 rats gave birth to an average of 9·3 young at 59·5 days of age, and 22 of them reared 96% of the young to weaning.


Author(s):  
Gil G. Rosenthal

This chapter focuses on social interactions, in the broadest sense, as sources of variation in mate choice and mating preferences. These interactions can be divided into three categories corresponding to when they are specified and which individuals are involved. The first includes effects that are determined before birth and transmitted vertically from parents: epigenetic modifications to the genome and the fetal or embryonic environment. The second includes influences between birth and sexual maturity, when the phenotypes of parents and/or other sexually mature, older individuals (oblique transmission) direct the development of preferences in choosers. Experience with courters and choosers after sexual maturity, or experience with other juveniles that shapes subsequent preferences, constitutes peer (horizontal) transmission.


2017 ◽  
Vol 95 (7) ◽  
pp. 473-483 ◽  
Author(s):  
Ximena González-Pisani ◽  
Pedro J. Barón ◽  
Laura S. López Greco

An integrative analysis of sexual maturity associated with growth was developed for the spider crab Leurocyclus tuberculosus (H. Milne Edwards and Lucas, 1842). Sexual maturity was characterized based on gonadal, morphological, morphometric, and functional sexual maturity. Progress in sexual maturation was described through 13 growth stages (instars) detected by the examination of size (carapace width) frequency distributions. Mature females displayed mature ovaries, developed vaginae, open gonopores, allometric changes in the abdomen, and ovigerous stage in the transition from instar IX to instar X. Sexually mature males presented spermatophores in the distal vasa deferentia and allometric changes in several measurements of the right chela in the transition from instar X to instar XI. However, two prepubertal phases were recognized in both sexes separated from each other by a prepubertal critical molt. Preceding the second critical molt, gonopores were sealed and vasa deferentia showed no spermatophores, and therefore neither sex was able to mate. The integrated analysis of size at maturity and size frequency distributions showed that in both sexes molt to gonadal, morphological, morphometric, and functional sexual maturity occurred in advance of the terminal molt, in contrast with patterns observed in other Majoidea.


1967 ◽  
Vol 45 (6) ◽  
pp. 979-989 ◽  
Author(s):  
H. J. Duncan ◽  
R. H. Common

The value of the quotient, 14CO2 liberated from glucose-1-14C over 14CO2 liberated from glucose-6-14C, for chicken liver slices has been determined. It did not deviate appreciably from unity for slices from (a) immature and sexually mature females, (b) a group of females at intervals during their transition from sexual immaturity to sexual maturity, (c) immature males, and (d) immature females treated by injection with estradiol monobenzoate. Incubation of the liver slices under anaerobic conditions reduced CO2 liberation to very low values and approximately doubled the quotient. Incubation in the presence of arsenite reduced oxidation but increased the quotient about fourfold. Incubation under anaerobic and aerobic conditions, with addition of pyruvate, increased the quotient value.It is concluded that the phosphogluconate-oxidative pathway, if active at all in chicken liver, plays a subordinate role in carbohydrate metabolism in this tissue compared with its role in carbohydrate metabolism in rat liver.


Parasitology ◽  
1967 ◽  
Vol 57 (1) ◽  
pp. 157-167 ◽  
Author(s):  
G. C. Kearn

Acanthocotylid (monogenean) parasites inhabit the skin of rays, and the lack of cilia on the infective larvae of these parasites may be an adaptation to the host's bottom-living habits.Freshly hatched larvae must remain on the sea-bottom until a ray settles on top of them, when the larvae then have the opportunity to attach themselves to the host's ventral surface. Acanthocotyle lobianchi, which infects Raia montagui and R. clavata at Plymouth, becomes sexually mature on the host's ventral surface and rarely wanders from it, but A. elegans, which is found on R. clavata only, migrates to the dorsal surface of the host before reaching sexual maturity.The larvae of acanthocotylids use their haptoral hooklets to attach themselves to the host's epidermis, but as the parasites increase in size the load on these hooks becomes acute. This load is relieved not as in other monogeneans by the development of hamuli but by the transformation of the posterior third of the larval body into an accessory ‘pseudohaptor’.I am obliged to the Director and Staff of the Plymouth Laboratory for laboratory facilities and to Mr J. E. Green for his interest and help on many occasions.


1966 ◽  
Vol 23 (5) ◽  
pp. 757-766 ◽  
Author(s):  
D. E. Sergeant

In less than a decade the mean age at sexual maturity of female harp seals of the Front, or northeastern Newfoundland population, decreased to 4 from [Formula: see text] years. Exploitation was heavy during this period and included a high proportion of seals older than 1 year. Females of the Gulf of St. Lawrence herd declined in mean age at sexual maturity over the same decade to 5 from nearly 6 years. Exploitation of this herd was lower, especially for animals older than their first year. Fertility of the adult females was likely higher in the more heavily exploited population. Published data on the White Sea population, which was reduced to low numbers, show reproduction at a lower mean age than for the present Front herd; for the Jan Mayen herd, of uncertain population status, about the same reproductive rate as the present Gulf herd. In most of the populations, samples of adult, whelped females showed the greatest number in the age-class about 1 year older than that first showing 100% of the females mature, as would be expected; however, samples from the Front herd showed dominance of an older age-class, suggesting that young adult females may to some extent segregate into separate groups. The immediate factors leading to increased reproductive rates at lower population densities were not elucidated.


1968 ◽  
Vol 128 (1) ◽  
pp. 69-83 ◽  
Author(s):  
Willys K. Silvers

In contrast to the uniform rejection of adult male skin isografts by C57BL/6 females, neonatal male skin isografts are frequently accepted. Moreover, 50% of all females which accept a neonatal male skin graft for 50 days accept a subsequent adult male skin graft as well. This ability of neonatal skin to produce tolerance has been investigated under a variety of experimental conditions. The results indicate: (a) Even when a newborn male skin graft is transplanted concomitantly with an adult graft, it can produce tolerance of the latter although it is less effective in this regard than when transplanted beforehand. (b) The continued exposure of the host to the newborn graft is vitally important in maintaining the unresponsive state; and most females deprived of these grafts for 50 days manifest an immune response when challenged with adult male skin. (c) Newborn male skin isografts raised on adult females are not as antigenic as normal male skin grafts. (d) Occasionally, even a presensitized female can be rendered tolerant by grafting with neonatal male skin. (e) Neonatal male skin grafts are not accepted when transplanted to the spleens of adult females although they may occasionally induce tolerance of a subsequent orthotopic adult male skin graft. The failure of these intrasplenic grafts to survive can be attributed at least partly to their small size since orthotopic grafts of comparable size usually do not survive. (f) Females bearing neonatal male skin grafts are not perceptible cellular chimeras. Because the unresponsive condition induced with neonatal skin is similar to that which results from multiparity, this latter condition has also received attention. In this regard it has been established that unlike the removal of a neonatal male skin isograft, the delayed grafting of isolated females with a previous history of multiparity does not result in many of them manifesting what may be considered an immune response. However, this delay in grafting does seem to impair the tolerance multiparity produces. The results are discussed in relation to other methods of producing tolerance in adult animals.


Parasitology ◽  
1987 ◽  
Vol 95 (3) ◽  
pp. 491-498 ◽  
Author(s):  
A. J. Probert ◽  
A. H. H. Awad

SUMMARYThe tegumental surface of Schistosoma margrebowiei as viewed by scanning electron microscopy is described. Both spined and unspined tubercles were found on the dorsal and dorso-lateral surfaces of sexually mature (in copula) male worms. Unpaired males lacked spined tubercles and the development of the spines is considered to occur only when worms are in copula. The females lack tubercles. The importance of tubercle structure in the identification of schistosome species and the effect of sexual maturity on their development is discussed.


1935 ◽  
Vol 1 (3) ◽  
pp. 213-226 ◽  
Author(s):  
W. Templeman

The claws of males and the width and depth of abdomen of females increase at a higher rate than body length with approaching sexual maturity. Consequently for lobsters over 20 cm. in length males possess claws relatively larger and females an abdomen relatively wider and deeper in an area such as that near Pointe du Chêne where sexual maturity occurs at about 20 cm. than in that near Grand Manan where lobsters only become sexually mature at about 34 cm.


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