Lagostomus maximus. En: SAyDS�SAREM (eds.) Categorizaci�n 2019 de los mam�feros de Argentina seg�n su riesgo de extinci�n.

2019 ◽  
Author(s):  
Sebasti�n Cirignoli ◽  
Bernardo Lartigau
Keyword(s):  
Author(s):  
Ruth Cwirenbaum ◽  
Alejandro R. Schmidt ◽  
Santiago A. Cortasa ◽  
María C. Corso ◽  
Alfredo D. Vitullo ◽  
...  

2017 ◽  
Vol 48 (3) ◽  
pp. 259-273 ◽  
Author(s):  
Pablo Ignacio Felipe Inserra ◽  
Santiago Elías Charif ◽  
Noelia Paula Di Giorgio ◽  
Lucía Saucedo ◽  
Alejandro Raúl Schmidt ◽  
...  

Reproduction ◽  
2011 ◽  
Vol 141 (5) ◽  
pp. 633-641 ◽  
Author(s):  
N P Leopardo ◽  
F Jensen ◽  
M A Willis ◽  
M B Espinosa ◽  
A D Vitullo

Apoptosis-dependent massive germ cell death is considered a constitutive trait of the developing mammalian ovary that eliminates 65–85% of the germinal tissue depending on the species. After birth and during adult lifetime, apoptotic activity moves from the germ cell proper to the somatic compartment, decimating germ cells through follicular atresia until the oocyte reserve is exhausted. In contrast, the South American rodent Lagostomus maximus shows suppressed apoptosis-dependent follicular atresia in the adult ovary, with continuous folliculogenesis and massive polyovulation, which finally exhausts the oocyte pool. The absence of follicular atresia in adult L. maximus might arise from a failure to move apoptosis from the germinal stratum to the somatic compartment after birth or being a constitutive trait of the ovarian tissue with no massive germ cell degeneration in the developing ovary. We tested these possibilities by analysing oogenesis, expression of germ cell-specific VASA protein, apoptotic proteins BCL2 and BAX, and DNA fragmentation by TUNEL assay in the developing ovary of L. maximus. Immunolabelling for VASA revealed a massive and widespread colonisation of the ovary and proliferation of germ cells organised in nests that disappeared at late development when folliculogenesis began. No sign of germ cell attrition was found at any time point. BCL2 remained positive throughout oogenesis, whereas BAX was slightly detected in early development. TUNEL assay was conspicuously negative throughout the development. These results advocate for an unrestricted proliferation of germ cells, without apoptosis-driven elimination, as a constitutive trait of L. maximus ovary as opposed to what is normally found in the developing mammalian ovary.


Author(s):  
Alejandro Raúl Schmidt ◽  
Pablo Ignacio Felipe Inserra ◽  
Santiago Andrés Cortasa ◽  
Sofía Proietto ◽  
Victoria Fidel ◽  
...  

2017 ◽  
Vol 31 (5) ◽  
pp. 517-534 ◽  
Author(s):  
Daniel J. Rafuse ◽  
Cristian A. Kaufmann ◽  
María A. Gutiérrez ◽  
Mariela E. González ◽  
Nahuel A. Scheifler ◽  
...  

2012 ◽  
Vol 32 (2) ◽  
pp. 183-187 ◽  
Author(s):  
Naira C.G Pieri ◽  
Alicia M. Flamini ◽  
Claudio G Barbeito ◽  
Juliana B Casals ◽  
Beatriz K Roque ◽  
...  

Entre as espécies de roedores já estudadas podemos destacar a grande variação na morfologia do aparelho reprodutor masculino. Assim, considerando a importância ecológica dos roedores, e a grande representatividade numérica quanto geográfica destes animais, bem como a escassez que aborda a anatomia reprodutiva, desenvolvemos este trabalho com um roedor histricomorfo da América do Sul, a viscacha. Este animal apresenta algumas características reprodutivas bem peculiares, desta forma descreveremos a anatomia macroscópica da musculatura perineal, e o papel dos músculos no comportamento copulatório desta espécie. A região perineal da viscacha é composta por cinco músculos, sendo que três músculos encontram-se dispostos no diafragama urogenital superficial, Musculus ischiocavernosus, M. bulbocavernosus e M. bulbospongiosus, e pelos músculos que se encontram no diafragma pélvico, M. levator ani e M. retractor penis. Sendo assim, destacamos que o estudo do assoalho pélvico em animais silvestres é de grande valia, uma vez que contribuem com o melhor entendimento dos mecanismos relacionados â ereção e ejaculação; ou seja colaboram com os estudos sobre a reprodução dos animais.


ISRN Anatomy ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
A. M. Cruceño ◽  
J. C. de Rosas ◽  
M. Fóscolo ◽  
E. M. Chaves ◽  
L. Scardapane ◽  
...  

The viscacha (Lagostomus maximus maximus) is a seasonal South American wild rodent. The adult males exhibit an annual reproductive cycle with periods of maximum and minimum gonadal activity. Four segments have been identified in the epididymis of this species: initial, caput, corpus, and cauda. The main objective of this work was to relate the seasonal morphological changes observed in the epididymal duct with the data from epididymal sperm during periods of activity and gonadal regression using light and scanning electron microscopy (SEM). Under light and electron microscopy, epididymal corpus and cauda showed marked seasonal variations in structural parameters and in the distribution of different cellular populations of epithelium. Initial and caput segments showed mild morphological variations between the two periods. Changes in epididymal sperm morphology were observed in the periods analyzed and an increased number of abnormal gametes were found during the regression period. During this period, anomalies were found mainly in the head, midpiece, and neck, while in the activity period, defects were found only in the head. Our results confirm that the morphological characteristics of the epididymal segments, as well as sperm morphology, undergo significant changes during the reproductive cycle of Lagostomus.


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