Duration of spermatogenesis and daily sperm production in the rodentProechimys guyannensis

Lara, Nathália de Lima e Martins; Santos, Ivan Carlos dos; Costa, Guilherme Mattos Jardim; Cordeiro-Júnior, D.A.; Almeida, Antonio Carlos; Madureira, Ana Paula; Zanini, Marcos Santos; França, Luiz R.

doi:10.1017/s0967199416000137

Cited by 6 publications

(4 citation statements)

References 56 publications

(111 reference statements)

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“… Abbreviations: LC = Leydig cell; DSP = Daily Sperm Production. References: [ a 77 , b 78 , b 79 , c 80 , c 81 , c 82 , d 83 , d 84 , e 85 , f 86 ]. …”

Section: Discussionmentioning

confidence: 99%

Testis structure, duration of spermatogenesis and daily sperm production in four wild cricetid rodent species (A. cursor, A. montensis, N. lasiurus, and O. nigripes)

2021

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Although rodents represent approximately 40% of all living mammalian species, our knowledge regarding their reproductive biology is still scarce. Due to their high vulnerability to environmental changes, wild rodents have become beneficial models for ecological studies. Thus, we aimed to comparatively investigate key functional testis parameters in four sexually mature wild rodent species (A. cursor, A. montensis, N. lasiurus, and O. nigripes). These species belong to the Cricetidae family, which is the most diverse family of rodents in South America, with a total of ~120 species in Brazil. The results found for the gonadosomatic index and the sickled sperm head shape observed strongly suggest that the species here evaluated are promiscuous, prolific, and short-lived. The duration of spermatogenesis was relatively short and varied from ~35–40 days. Both the percentage of seminiferous tubules (ST) in the testis parenchyma (~95–97%) and the number of Sertoli cells (SC) (~48–70 million) per testis gram were very high, whereas a fairly good SC efficiency (~8–13 round spermatids per SC) was observed. In comparison to other mammalian species studied, particularly the rodents of the suborder Myomorpha (i.e. hamsters, rats and mice), the rodents herein investigated exhibited very high (~62–80 million) daily sperm production per testis gram. This impressive spermatogenic efficiency resulted mainly from the short duration of spermatogenesis and quite high values found for the ST percentage in the testis and the SC number per testis gram. We expect that the knowledge here obtained will help conservation programs and the proper management of wildlife.

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“… Abbreviations: LC = Leydig cell; DSP = Daily Sperm Production. References: [ a 77 , b 78 , b 79 , c 80 , c 81 , c 82 , d 83 , d 84 , e 85 , f 86 ]. …”

Section: Discussionmentioning

confidence: 99%

Testis structure, duration of spermatogenesis and daily sperm production in four wild cricetid rodent species (A. cursor, A. montensis, N. lasiurus, and O. nigripes)

2021

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“…In the vaginal membrane experiments, we observed closed and pin-prick states even during the estrus stage, which may represent an obstacle to mating even in the fertile period. This fact is inconsistent with the highest spermatogenic efficiency observed in males P. guyannensis (Lara et al., 2016) . In another species of Proechimys (P. guairae) a lower frequency of vaginal opening was also observed during the estrous cycle (Lusty and Seaton, 1978); however, in other Hystricomorph rodents, such as guinea pigs, the vaginal opening is associated with the estrous cycle (Lilley et al., 1997).…”

Section: Discussionmentioning

confidence: 61%

Characterization of the estrous cycle in the Amazon spiny rat (Proechimys guyannensis)

Sanabria

Bittencourt

Rosa

et al. 2019

Heliyon

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Males of Proechimys guyannensis, a rodent living in the Amazon rainforest are studied in biomedical research because of their antiepileptogenic mechanism. Females are usually taken from experimental designs, because of limited data of this sex. This study aimed to characterize the estrous cycle to include females together with males in research in a more balanced approach. The estrous cycle of P. guyannensis based through exfoliative cytology, determination of the vaginal occlusion membrane state, and hormonal analysis. In this study, cytological analyses of vaginal smears were performed for three months, three times a day. The observed length of the estrous cycle was 247 ± 81 h (mean ± SD) with a reproductive phase of 27.08 ± 17.39 h (estrus stage). We observed a frequent presence of both the open and closed states of the vaginal membrane in the estrus stage (fertile period) although only the open stage is a prerequisite for successful copulation. High levels of progesterone and estradiol were detected in proestrus. Levels of follicle-stimulating hormone peaked at the estrus stage. These data will establish the parameters and subsidies to set the grounds for future research either for investigating the biology of this species or to use P. guyannensis in research that previously excluded females. Information regarding female Proechimys is relevant to not only describe the species but also explain the interaction between sex hormones and physiological responses. Moreover, the present results will enhance rigor and reproducibility in preclinical studies. In conclusion, P. guyannensis reproductive cycles can occur spontaneously and cyclically independent of mating stimulation and the high levels of FSH in the estrus stage, suggest that ovulation occurs in the late phase of the estrus.

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“…Rats were postnatal day (PND) 30-33 at the start of the drinking paradigm. Eight weeks, to wait for the completion of one spermatogenesis cycle (Lara et al, 2016;van Haaster & de rooij, 1993), after the last drinking session, the 10 highest drinking males (D0) and the non-drinking controls (ND0) were mated with ethanol naïve females. Of the remaining 10 males, the 6 highest drinkers were culled for sample collection after the last day of drinking for molecular analysis (explained in Chapter 5).…”

Section: Subjectsmentioning

confidence: 99%

“…The choosing of the highest 10 drinkers for mating was to make sure our sire rats had consistently consumed high amounts of alcohol. Those selected for mating were housed individually for the length of 1 spermatogenesis cycle (about 8 weeks) before being mated with ethanol naïve females (Lara et al, 2016;van Haaster & de rooij, 1993). The pairs were kept together for 20 days after which they were separated, this occurred once and therefore if a sire was unable to impregnate a female in that time it produced no F1 litters.…”

Section: Study Mating Structurementioning

confidence: 99%

Transgenerational Hangovers: A Rat Model for Behavioural and Epigenetic Changes Across Generations due to Paternal Preconceptual Alcohol Consumption

Hussain

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Alcohol is the most harmful drug of abuse, making alcoholism a major economic and public health crisis. Unsurprisingly, this has led to the majority of neurobiological research on alcohol focussing on its direct effects on an individual. This includes those affected by foetal alcohol spectrum disorders (FASDs). However, research has shown that heavy paternal drinking predicts earlier and heavier adolescent drinking in the offspring, accompanied with other behavioural and molecular changes. While alcohol use disorder (AUD) is highly heritable, research on genetic variants alone does not sufficiently account for its risk and the FASDs like symptoms seen in the offspring of alcoholic fathers. Recently, there has been an increase in appreciation of the importance of epigenetic mechanisms of inheritance, which transfer changes due to parental experiences through the germline. This thesis aimed to assess both the inter and transgenerational impacts of preconceptual paternal alcohol consumption (PPAC) using a rat model. Sprague Dawley male rats (F0) underwent chronic voluntary ethanol intake and at the end of the drinking paradigm were kept for one spermatogenesis cycle before being mated with ethanol naïve females. The litters and matched controls were behaviourally assessed, and a cohort of F1 males mated to observe a F2 generation.PPAC caused behavioural changes in both the F1 and F2 generations, including altering litter sizes and delaying development. The F1 also show a reduction in sensitivity to the motor impairing effects of ethanol compared to controls. Sexually dimorphic effects of PPAC were seen with female offspring having a reduced preference to ethanol in both the F1 and F2, while tolerance to ethanol in motor coordination was again seen in the F2 females but not F2 males. Likewise, F1 males presented reductions in locomotor activity but these effects did not persist in the F2.Analysis of liver mitochondrial DNA copy number (mtDNA-CN) found that drinking F0 fathers had reduced mtDNA-CN at the end of the ethanol intake paradigm and 12 weeks post-drinking relative to controls. The livers of F1 showed lower mtDNA-CN in the offspring of ethanol sired rats compared to offspring of non-drinkers after undergoing ethanol consumption, suggesting differences in liver metabolism. Finally, livers of F0 drinkers had reduced expression of Peroxisome proliferator-activated receptor γ coactivator 1α (Pgc1a), relating to mitochondrial biogenesis, and methyl-CpG-binding protein 2 (Mecp2), indicating putative changes in methylation signalling, together suggesting epigenetic inheritance of changes due to xenotoxic stress.The findings show PPAC induces developmental delays, causes transgenerational changes in drinking behaviour, ethanol sensitivity and liver mitochondrial function in a sexually dimorphic manner. These changes may be protective to the female offspring of PPAC to modify their ethanol intake. The alterations in F1 liver mtDNA-CN demonstrate potential far-reaching consequences for the metabolism of xenotoxic substances extending beyond ethanol and provides evidence to support behavioural and epigenetic changes across generations due to PPAC.

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Duration of spermatogenesis and daily sperm production in the rodentProechimys guyannensis

Cited by 6 publications

References 56 publications

Testis structure, duration of spermatogenesis and daily sperm production in four wild cricetid rodent species (A. cursor, A. montensis, N. lasiurus, and O. nigripes)

Testis structure, duration of spermatogenesis and daily sperm production in four wild cricetid rodent species (A. cursor, A. montensis, N. lasiurus, and O. nigripes)

Characterization of the estrous cycle in the Amazon spiny rat (Proechimys guyannensis)

Transgenerational Hangovers: A Rat Model for Behavioural and Epigenetic Changes Across Generations due to Paternal Preconceptual Alcohol Consumption

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