Avian Testicular Structure, Function, and Regulation

Deviche, Pierre; Hurley, Laura L.; Fokidis, H. Bobby

doi:10.1016/b978-0-12-374929-1.10002-2

Cited by 25 publications

(36 citation statements)

References 496 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…European starlings, Sturnus vulgaris, with reduced body mass as a result of experimentally changing the daily duration of food availability also have underdeveloped testes (Dawson, 1986;Meijer, 1991), but testis growth is unaffected by food availability in Abert's towhees (Davies et al, 2015a). Seasonal testicular growth is primarily due to proliferation of Sertoli cells, which make up the majority of the mass in developed testes (Deviche et al, 2011;Young et al, 2001). In this study, we found that the smaller testes under food restriction can be at least partially attributed to smaller seminiferous tubules.…”

Section: Testicular Response To Energetic Deficitmentioning

confidence: 99%

Food restriction negatively affects multiple levels of the reproductive axis in male house finches, Haemorhous mexicanus

Valle

Carpentier

et al. 2015

Journal of Experimental Biology

Self Cite

View full text Add to dashboard Cite

Nutrition influences reproductive functions across vertebrates, but the effects of food availability on the functioning of the hypothalamicpituitary-gonadal (HPG) axis in wild birds and the mechanisms mediating these effects remain unclear. We investigated the influence of chronic food restriction on the HPG axis of photostimulated house finches, Haemorhous mexicanus. Food-restricted birds had underdeveloped testes with smaller seminiferous tubules than ad libitum-fed birds. Baseline plasma testosterone increased in response to photostimulation in ad libitum-fed but not in food-restricted birds. Food availability did not, however, affect the plasma testosterone increase resulting from a gonadotropin-releasing hormone-I (GnRH) or a luteinizing hormone (LH) challenge. The number of hypothalamic GnRH immunoreactive (ir) but not proGnRH-ir perikarya was higher in food-restricted than in ad libitum-fed finches, suggesting inhibited secretion of GnRH. Hypothalamic gonadotropin-inhibitory hormone (GnIH)-ir and neuropeptide Y (NPY)-ir were not affected by food availability. Plasma corticosterone (CORT) was also not affected by food availability, indicating that the observed HPG axis inhibition did not result from increased activity of the hypothalamic-pituitaryadrenal (HPA) axis. This study is among the first to examine multilevel functional changes in the HPG axis in response to food restriction in a wild bird. The results indicate that food availability affects both hypothalamic and gonadal function, but further investigations are needed to clarify the mechanisms by which nutritional signals mediate these effects.

show abstract

Section: Testicular Response To Energetic Deficitmentioning

confidence: 99%

Food restriction negatively affects multiple levels of the reproductive axis in male house finches, Haemorhous mexicanus

Valle

Carpentier

et al. 2015

Journal of Experimental Biology

Self Cite

View full text Add to dashboard Cite

show abstract

“…A consistent effect of urbanization on bird populations is an advancement of the timing of seasonal gonadal development (Deviche et al, 2010; reviewed by Deviche and Davies, 2014;Partecke et al, 2005). Although this phenomenon appears to be widespread, a lack of mechanistic studies means that the underlying mechanism(s) remain(s) largely unknown.…”

Section: Introductionmentioning

confidence: 99%

Advanced seasonal reproductive development in a male urban bird is reflected in earlier plasma luteinizing hormone rise but not energetic status

Davies

Behbahaninia

Giraudeau

et al. 2015

General and Comparative Endocrinology

Self Cite

View full text Add to dashboard Cite

Urban animals inhabit an environment considerably different than do their non-urban conspecifics, and to persist urban animals must adjust to these novel environments. The timing of seasonal reproductive development (i.e., growth of gonads and secondary sex organs) is a fundamental determinant of the breeding period and is frequently advanced in urban bird populations. However, the underlying mechanism(s) by which birds adjust the timing of reproductive development to urban areas remain(s) largely unknown. Here, we compared the timing of vernal reproductive development in free-ranging urban and non-urban male Abert's Towhees, Melozone aberti, in Phoenix, Arizona, USA, and tested the non-mutually exclusive hypotheses that earlier reproductive development is due to improved energetic status and/or earlier increase in endocrine activity of the reproductive system. We found that urban birds initiated testicular development earlier than non-urban birds, but this disparity was not associated with differences in body condition, fat stores, or innate immune performance. These results provide no support for the hypothesis that energetic constraints are responsible for delayed reproductive development of non-urban relative to urban male Abert's Towhees. Urban birds did, however, increase their plasma luteinizing hormone, but not plasma testosterone, earlier than non-urban birds. These findings suggest that adjustment to urban areas by Abert's Towhees involves increases in the endocrine activity of the anterior pituitary gland and/or hypothalamus earlier than non-urban towhees.

show abstract

“…Although some authors that worked in different species reported results dissimilar from those of this work, Perry (1960) and Etches (1996) in cockerels and Jibril et al (2011) in rams, other authors have however reported similar results like in the rabbit (Ladokun et al, 2006), bull (Rekwot et al, 1988) and drakes (Ghonim et al, 2010). These apparent differences and similarities are perhaps because optimal crude protein requirement differs between species or even between breeds of same species (Deviche et al, 2011). The reserves are similar to the result of Cecil et al (1988) Cecil et al (1988) suggest that with optimum environmental conditions such as adequate feed supply, the Nigerian indigenous turkey breed can parallel their exotic counterpart in reproductive capacity.…”

Section: Discussionmentioning

confidence: 93%

“…The main function of the testis is sperm production. The epididymis aids in transport and the vas deferens serves both for storage and maturation of sperm (Deviche et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

Testicular morphometry and sperm reserves of local turkey toms fed varying levels of protein in the diet

Yahaya¹,

Nwannenna²,

Fadason³

et al. 2017

Sokoto J. Vet. Sc.

View full text Add to dashboard Cite

The morphometry and sperm reserves of the testis, epididymis and vas deferens of three groups (n=5/ group) of sexually active adult local turkey toms fed isocaloric diet with varying levels (12 %, 16 %, 20 %) of protein were studied for sixteen weeks. The weights of the toms before treatment were between 3.5 -4.5 kg, while at the end of the experiment the mean ± SD live weight were 5.29 ± 0.65, 5.39 ± 0.45 and 5.63 ± 0.49 kg for groups 1, 2 and 3 respectively. The mean ± SD weights of the paired tunics, testis, epididymis and vas deferens, respectively, were 0.41 ± 0.11 g, 8.27 ± 2.37 g, 0.28 ± 0. 07 g and 0.36 ± 0.11 g (group 1): 0.43 ± 0.02 g, 8.50 ± 0.65 g, 0.33 ± 0.11 g and 0.40 ± 0.11 g (group 2) and: 0.49 ± 0.16 g, 9.83 ± 3.08 g, 0.40 ± 0.13 g and 0.50 ± 0.18 g, (group 3). The mean ± SD lengths of the testes were: 3.72 ± 0.34 cm, 4.40 ± 0.47 cm and 4.48 ± 1.14 cm; the epididymis: 3.12 ± 0.56 cm, 3.17 ± 0.67cm and 3.48 ± 0.49 cm, and the vas deferens: 17.27 ± 1.10 cm, 17.33 ± 0.93 cm and 17.49 ± 1.10 cm, for groups 1, 2 and 3, respectively. Mostly, the parameters of the left organs were greater than those of the right. The mean ± SD weight of the testes positively correlated with that of the epididymis in all the groups (r = 0.72, 0.65 and 0.87 for groups 1, 2 and 3 respectively) and the vas deferens (r = 0.54, 0.72 and 0.75 for groups 1, 2 and 3 respectively). The gonadal sperm reserves were 0.19 ± 0.00 x 10 9 cells/ml, 0.21 ± 0.00 x 10 9 cells/ml and 0.21 ± 0.00 x 10 9 cells/ml for groups 1, 2 and 3 respectively. The mean ± SD extragonadal sperm reserves were, epididymis: 0.08 ± 0.00 x 10 9 cells/ml, 0.12 ± 0.01 x 10 9 cells/ml, 0.18 ± 0.00 x 10 9 cells/ml, and vas deferens: 2.00 ± 0.13 x 10 9 cells/ml, 2.82 ± 0.50 x 10 9 cells/ml and 3.75 ± 0.60 x 10 9 cells/ml for the three groups respectively. The vas deferens had about 88 %, of the extragonadal sperm reserve in group 1 and 90 % in groups 2 and 3. Sperm reserve was positively correlated to body weight and to the length of the testis. The results suggest, therefore, that morphometry and sperm reserves were better in turkey toms fed 16 % and 20 % than 12 % protein diets.

show abstract

Avian Testicular Structure, Function, and Regulation

Cited by 25 publications

References 496 publications

Food restriction negatively affects multiple levels of the reproductive axis in male house finches, Haemorhous mexicanus

Food restriction negatively affects multiple levels of the reproductive axis in male house finches, Haemorhous mexicanus

Advanced seasonal reproductive development in a male urban bird is reflected in earlier plasma luteinizing hormone rise but not energetic status

Testicular morphometry and sperm reserves of local turkey toms fed varying levels of protein in the diet

Contact Info

Product

Resources

About