Effect of puberty and sexual development on daily sperm production and epididymal sperm reserves of Piau boars

Castro, Alexandre Fonseca de; Cardoso, F.M.; França, Luiz R.

doi:10.1016/0378-4320(91)90011-n

Cited by 10 publications

(3 citation statements)

References 18 publications

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“…However, Meishan boars undergo pubertal testicular development at a much younger age than Piau boars. Growth of seminiferous tubules to a mean diameter of 100 m occurs before 50 d of age in Meishan boars [17][18][19], but the seminiferous tubules of Piau boars do not achieve this diameter until after 120 d of age [20,21], and the size of postpubertal testes of Piau boars is greater than in Meishan boars. Furthermore, our second study provided no support for a correlation of testicular diameter early in pubertal development with testicular size of adult boars.…”

Section: Discussionmentioning

confidence: 99%

Assessment of pubertal development of boars derived from ultrasonographic determination of testicular diameter

Ford

Wise

2011

Theriogenology

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At the onset of puberty, seminiferous tubules rapidly increase in diameter, thereby occupying a greater proportion of the testis, resulting in a rapid increase in testicular size. The objective of the current studies was to evaluate ultrasonography for assessing testicular diameter, as a basis for ranking boars relative to their extent of pubertal development. In the initial study, prior to castration at 4, 5, 6, or 7 mo of age, testicular length and diameter were assessed by ultrasonography in 160 anesthetized boars. After castration, testes were weighed. Mean diameter of seminiferous tubules and percentage of the testis occupied by tubules were determined by histological evaluations of all testes. Testicular volume was calculated from length and diameter and was correlated with testicular weight (P < 0.001; r ≧ 0.78) within each of the four age groups. At 4 and 5 mo of age, testicular diameter correlated positively (P < 0.001) with diameter of seminiferous tubules; this relationship was not significant at older ages. In two subsequent studies, testicular diameter determined ultrasonographically in conscious boars was highly correlated (r > 0.8) when assessed twice on the same day, or when diameter of the right was compared with diameter of the left testis. Similarly, testicular diameter obtained initially at 92 d of age correlated positively (P < 0.001) with the diameter observed at older ages, but the magnitude of the relationship decreased as time between evaluations increased. These findings supported ultrasonographic determination of testicular diameter during early pubertal development, as a means to rank boars of similar chronological age for extent of pubertal development.

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Section: Discussionmentioning

confidence: 99%

Assessment of pubertal development of boars derived from ultrasonographic determination of testicular diameter

Ford

Wise

2011

Theriogenology

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“…[24][25][26]41,42 Nevertheless, it is well known that the testis increases in size well into adulthood, with a significant increase in total lengths of the seminiferous tubules, but without a further increase in tubular diameter and SC efficiency. 19,43 However, a satisfactory explanation for this tubular lengthening has not been presented until now. Immature Sox-9 positive SCs, capable of proliferation, were found in the transition region of the seminiferous tubules, adjacent to the rete testis.…”

Section: 1338-40mentioning

confidence: 99%

“…3,15,16 However, suggesting that SCs may still proliferate in some areas of the testis, even after the stabilization of the tubular diameter and SC efficiency (number of germ cells per SC) in early puberty, the testis continues to grow, with significant increases in weigh, sperm production and tubular length during the post-puberty period in several mammalian species investigated. [16][17][18][19][20][21][22][23][24] Although challenging the dogma that SCs do not proliferate in pre-pubertal and sexually mature mammals has been controversial, some mammalian seasonal breeders have been reported to show season-dependent variations in SC proliferation activity. [24][25][26] In all vertebrates spermatogenesis occurs in the seminiferous tubules (ST).…”

Section: Introductionmentioning

confidence: 99%

Sertoli cells are capable of proliferation into adulthood in the transition region between the seminiferous tubules and the rete testis in Wistar rats

et al. 2016

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Sertoli cells (SCs) play a crucial role in testis differentiation, development and function, determining the magnitude of sperm production in sexually mature animals. For over 40 years, it has been considered that these key testis somatic cells stop dividing during early pre-pubertal phase, between around 10 to 20 days after birth respectively in mice and rats, being after that under physiological conditions a stable and terminally differentiated population. However, evidences from the literature are challenging this dogma. In the present study, using several important functional markers (Ki-67, BrdU, p27, GATA-4, Androgen Receptor), we investigated the SC differentiation status in 36 days old and adult Wistar rats, focusing mainly in the transition region (TR) between the seminiferous tubules (ST) and the rete testis. Our results showed that SCs in TR remain undifferentiated for a longer period and, although at a lesser degree, even in adult rats proliferating SCs were observed in this region. Therefore, these findings suggest that, different from the other ST regions investigated, SCs residing in the TR exhibit a distinct functional phenotype. These undifferentiated SCs may compose a subpopulation of SC progenitors that reside in a specific microenvironment capable of growing the ST length if needed from this particular testis region. Moreover, our findings demonstrate an important aspect of testis function in mammals and opens new venues for other experimental approaches to the investigation of SC physiology, spermatogenesis progression and testis growth. Besides that, the TR may represent an important site for pathophysiological investigations and cellular interactions in the testis.

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Association of allelic variants of thyroid-binding globulin with puberty in boars and responses to hemicastration

Ford¹,

Rohrer²,

Nonneman³

et al. 2010

Animal Reproduction Science

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Effect of puberty and sexual development on daily sperm production and epididymal sperm reserves of Piau boars

Cited by 10 publications

References 18 publications

Assessment of pubertal development of boars derived from ultrasonographic determination of testicular diameter

Assessment of pubertal development of boars derived from ultrasonographic determination of testicular diameter

Sertoli cells are capable of proliferation into adulthood in the transition region between the seminiferous tubules and the rete testis in Wistar rats

Association of allelic variants of thyroid-binding globulin with puberty in boars and responses to hemicastration

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