Uterine histology and reproductive cycles in pregnant and non-pregnant opossums, Didelphis virginiana

Fleming, Michael W.; Harder, John D.

doi:10.1530/jrf.0.0630021

Cited by 32 publications

(16 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Th e two testicles of G. Microtarsus are round and conditioned within the scrotum in the inguinal region, in a pendular mode and cranially to the penis, as described by Fleming and Harder (1981) for Didelphis virginiana and by Barros et al (2003) to Didelphis sp.…”

Section: Discussionmentioning

confidence: 87%

Morphological study of the male genital organs of Gracilinanus microtarsus

Lima

Santos

Viana

et al. 2013

Braz. J. Vet. Res. Anim. Sci.

View full text Add to dashboard Cite

Gracilinanus microtarsus is one of the smallest marsupials on earth. Since it spreads seeds, it has great ecological relevance. However, its reproduction data, especially those related to the anatomy of its reproduction apparatus, are scarce in the literature. Current analysis describes the male genital organs of six adult specimens of G. microtarsus. Macroscopic studies were undertaken on dissected organs, whereas histological studies were performed by inclusion technique in paraffin and by hematoxylin and eosin, and Masson trichrome staining. The male genital organs and accessory glands of G. microtarsus consist of two testicles within a pendular scrotum, placed cranially to the penis, featuring a histology consisting of seminiferous tubules with spermatogenic cells, spermatozoa and Sertoli cells, and a peritubular region with Leydig cells; testicles closely associated with epididymis with head, body and tail, with histological differences between the different regions; deferent ducts; funiculus spermaticus; accessory glands composed of prostate, divided into three distinct segments and bulbourethral glands; pelvic and penile urethra and penis with bifid glans. Results show that the male genital organs and accessory glands of G. Microtarsus are anatomically similar to that found in Didelphis sp. and other marsupials groups, with slight details such as the site of each organ.Keywords: Didelphimorphia. Marsupials. Reproduction. Prostatic segments. ResumoGracilinanus microtarsus é um dos menores marsupiais do mundo. Possui grande potencial dispersor de sementes e por esta razão apresenta grande importância ecológica. No entanto, dados em relação à reprodução desses animais são escassos na literatura, principalmente, aqueles relacionados à anatomia dos órgãos do aparelho reprodutor. Por essa razão, objetivamos com este estudo realizar uma descrição dos órgãos genitais masculinos em seis exemplares de G. microtarsus adultos. Para tanto, realizamos estudos macroscópicos por dissecação dos órgãos e estudos histológicos por técnica de inclusão em parafina e coloração em hematoxilina e eosina, e tricromo de Masson. Encontramos, que os órgãos genitais masculinos e glândulas acessórias em G. microtarsus são representados por dois testículos localizados dentro de um escroto pendular, posicionados cranialmente ao pênis, cuja histologia revelou túbulos seminíferos com espermatogônias, espermatozoides e células de Sertoli e região peritubular com células de Leydig; testículos em íntima associação com os epidídimos, divididos em cabeça, corpo e cauda, com diferenças histológicas entre as diferentes regiões; ductos deferentes; funículo espermático; glândulas anexas compostas pelas glândulas prostáticas divididas em três distintos segmentos e glândulas bulbouretrais; uretra pélvica e peniana e um pênis com glande bífida. Concluímos que os órgãos genitais e as glândulas acessórias masculina de G. microtarsus, anatomicamente são muito semelhantes aos dos Didelphis sp. e outros grupos de marsupiais, diferenciando-se apenas...

show abstract

Section: Discussionmentioning

confidence: 87%

Morphological study of the male genital organs of Gracilinanus microtarsus

Lima

Santos

Viana

et al. 2013

Braz. J. Vet. Res. Anim. Sci.

View full text Add to dashboard Cite

show abstract

“…During pregnancy, the uteri of all marsupial species so far described becomes highly secretory (the potoroo, Shaw and Rose, 1979;brushtail possum, Arnold and Shorey, 1985;Shorey and Hughes, 1973; the brown antechinus, Cruz and Selwood, 1993; the stripe-faced dunnart, Selwood, 1997, Selwood andWoolley, 1991; and the Virginia opossum, Fleming andHarder, 1981, Padykula andTaylor, 1976). However, the uterine response during pregnancy in the period after embryonic diapause is most extensively described in the tammar (Renfree, 1972, Renfree, 1973a, Renfree and Tyndale-Biscoe, 1973, Shaw, 1996.…”

Section: The Uterusmentioning

confidence: 99%

Embryo-endometrial interactions during early development after embryonic diapause in the marsupial tammar wallaby

Renfree¹,

Shaw²

2014

Int. J. Dev. Biol.

View full text Add to dashboard Cite

The marsupial tammar wallaby has the longest period of embryonic diapause of any mammal. Reproduction in the tammar is seasonal, regulated by photoperiod and also lactation. Reactivation is triggered by falling daylength after the austral summer solstice in December. Young are born late January and commence a 9-10-month lactation. Females mate immediately after birth. The resulting conceptus develops over 6-7 days to form a unilaminar blastocyst of 80-100 cells and enters lactationally, and later seasonally, controlled diapause. The proximate endocrine signal for reactivation is an increase in progesterone which alters uterine secretions. Since the diapausing blastocyst is surrounded by the zona and 2 other acellular coats, the mucoid layer and shell coat, the uterine signals that maintain or terminate diapause must involve soluble factors in the secretions rather than any direct cellular interaction between uterus and embryo. Our studies suggest involvement of a number of cytokines in the regulation of diapause in tammars. The endometrium secretes platelet activating factor (PAF) and leukaemia inhibitory factor, which increase after reactivation. Receptors for PAF are low on the blastocyst during diapause but are upregulated at reactivation. Conversely, there is endometrial expression of the muscle segment homeobox gene MSX2 throughout diapause, but it is rapidly downregulated at reactivation. These patterns are consistent with those observed in diapausing mice and mink after reactivation, despite the very different patterns of endocrine control of diapause in these 3 divergent species. These common patterns suggest a similar underlying mechanism for diapause, perhaps common to all mammals, but which is activated in only a few.

show abstract

“…The composition of secreted proteins differs between the two uteri in M. eugenii (Renfree 1973), and in T. vulpecula the mitotic rate of the ipsilateral glandular epithelium is significantly higher on day 2 post-oestrus (Von der Borch 1963), equivalent to day 1 post-ovulation (Shorey & Hughes 1973b). In the polyovular dasyurids A. agilis (Cruz & Selwood 1993) and Sminthopsis macroura (Cruz & Selwood 1997), the endometrial stroma, luminal and glandular epithelium are significantly thicker in pregnant cycles compared with non-pregnant cycles at specific stages of the luteal phase, but in the polyovular didelphid Didelphis virginiana, the non-pregnant uterine endometrium is significantly thicker on day 11 (Fleming & Harder 1981), the day of implantation (Hartman 1928).…”

Section: Introductionmentioning

confidence: 97%

“…However, pregnancy-specific hormonal and morphological changes are found during gestation in both monovular (Von der Borch 1963, Renfree 1972, 1973, Renfree & Tyndale-Biscoe 1973, Cake et al 1980, Hinds & Tyndale-Biscoe 1982, Curlewis & Stone 1986) and polyovular (Fleming & Harder 1981, Fletcher 1989, Hinds 1989, Cruz & Selwood 1993, 1997 marsupial species.…”

Section: Introductionmentioning

confidence: 99%

Progesterone concentration in the marsupial Sminthopsis macroura: relationship with the conceptus, uterine glandular regeneration and body weight

2009

View full text Add to dashboard Cite

Close examination of hormonal profiles and uterine morphology in the marsupial reproductive cycle highlights significant differences between pregnant and non-pregnant cycles. In the polyovular dasyurid marsupial Sminthopsis macroura, we identified changes associated with gestation by comparing ovarian and plasma progesterone concentrations, uterine weights, uterine epithelial mitoses, body weights and gestation lengths between pregnant and non-pregnant luteal phases. The plasma progesterone profile of S. macroura was biphasic, peaking during unilaminar blastocyst expansion and on the day of implantation. Periods of rapid embryonic development were associated with increasing plasma progesterone concentrations and animal body weight. For the first time in a polyovular marsupial, we identified 1) a correlation between ovarian progesterone concentration and conceptus number during the luteal phase just prior to implantation (total ovarian progesterone), indicating a conceptus influence on progesterone concentration; 2) a pulse of uterine epithelial mitotic activity at the time of implantation and 3) increased mitotic activity in pregnant animals during unilaminar blastocyst formation compared with non-pregnant animals. Gestation length was reduced by up to 15%, due to the loss of, or reduction in, the fourcell arrest and more rapid definitive blastocyst expansion. This is the first time a conceptus influence on gestation length has been identified in a dasyurid. This study provides further evidence for the modification of the luteal phase by pregnancy in S. macroura.

show abstract

Uterine histology and reproductive cycles in pregnant and non-pregnant opossums, Didelphis virginiana

Abstract: Summary. Uteri

Cited by 32 publications

References 11 publications

Morphological study of the male genital organs of Gracilinanus microtarsus

Morphological study of the male genital organs of Gracilinanus microtarsus

Embryo-endometrial interactions during early development after embryonic diapause in the marsupial tammar wallaby

Progesterone concentration in the marsupial Sminthopsis macroura: relationship with the conceptus, uterine glandular regeneration and body weight

Contact Info

Product

Resources

About