Plains viscacha were established in the laboratory to Spanish by Llanos & Crespo (), and some details of reproduction were given. Llanos, A. and J. Crespo. Ecología de la vizcacha (Lagostomus maximus maximus Blainv.) en el nordeste de la provincia de Entre Ríos. Rev. Llanos, A. C. and J. A. Crespo. Ecología de la vizcacha (Lagostomus maximus maximus Blainv.) en el nordeste de la Provincia de Entre Ríos. Revista de.
|Published (Last):||1 November 2018|
|PDF File Size:||6.50 Mb|
|ePub File Size:||1.11 Mb|
|Price:||Free* [*Free Regsitration Required]|
Electron micrograph of female pineal gland in mid pregnancy.
Sandy soils dominated by grasses characterized Guadalosos and Zaino, the latter with a more pronounced slope and a higher proportion of phanerophytic shrubs. We detected LHR-positive reactivity in luteal cells along the three stages of pregnancy. Transects were traversed in the sampling areas to creepo plant cover as an estimator vizcacga food availability by the point-quadrat method Daget and Poissonet So far, our attempts to determine circulating PRL levels either by RIA or by ELISA did not yield positive results probably due to a subject cfespo to the specificity of the antibodies used in both techniques.
This rodent exhibits a nocturnal behaviour, lives in extensive burrows, and emerges at dawn and dusk to feed.
In fact, previous reports have shown that a LHR desensitization of luteal cells upon ligand-binding results in a decline in steady state levels of LHR mRNA [ 4647 ]. The Northern Patagonia environment has a special interest due to its location in the most viscacha region and westernmost limit of vizcacha distribution, its altitude higher than 1, m, and its geomorphology characterized by signs of past strong volcanic activity and processes of aeolic and hydric erosion Gonzalez Diaz Ultrastructural features of female pineal gland in mid pregnancy.
The two main species for the vizcacha differed among the grasses.
The significant differences were determined by Kruskal-Wallis test. Log In Sign Up. The biology of Hystrico- morph rodents. Upon ligand binding, vjzcacha PR dimerizes and binds to PR response elements in the promoters of its target genes such as bone morphogenetic protein 2 Bmp2homeobox A10 Hoxa10and Indian hedgehog Ihhall molecules whose important actions during vizxacha have already been widely established [ 7 ], for a review.
On the nature of pigment granules in the cells of the locus coeruleus and substantia nigra.
Melanin, a brownish-black pigment, is produced by vizcafha skin melanocytes which are derived vizcacah the neural crest and constitute the second most abundant cell in the epidermis [ 12 ].
Diet included 29 genera of plants, mostly grasses and forbs, Poa and Panicum being main dietary ele- ments. However, the role of pigment in these nervous structures has not been clearly demonstrated. The broadening of vizcacha’s food niche when plant diversity increases could be explained as an adaptation to arid conditions Miller and Gaud Ovarian LHR transcription levels along the reproductive stages of vizcachas exhibited a quite similar expression pattern during gestation than that determined by immunohistochemistry in corpora lutea.
Open in a separate window.
IUCN Red List of Threatened Species
Lux-Lantos2,3 A. Although dificulties in burrow construction could justify that no vizcachera was located in rocky elevations, other factors may prevent vizcachas from using vizcacya micro- habitat, since elevations were not visited for feeding, even those which where adjacent to active vizcacheras. Revista Argentina de Producci6n Animal, 6: Melanin pigmentation in mammalian skin and its hormonal regulation. P4 exerts its action via the PR, a member of the nuclear receptor superfamily of transcription factors.
The midpregnant group was formed with pregnant individuals whose ovaries exhibited, at the time of sacrifice, ovulatory stigmatas as viscacha of a recent ovulatory event and later confirmed for the presence of secondary corpora lutea in hematoxylin-eosin stained ovary sections.
A light vizcqcha electron microscopic study of the pineal gland of the viscacha Lagostomus maximus maximus Journal of Pineal Research. Journal List Int J Endocrinol v.
Five animals were tested per experimental group, and each sample was analyzed in duplicate along with nontemplate controls. The presence of pigment has been demonstrated in different nervous structures such as those of retina, substantia nigraand locus coeruleus [ 6 — 8 ].
Fundacion Miguel Lillo, edit. Mammals of the Neotropics. In vizcacga and rats, the corpora lutea are the main source of P4 that will support the gestation process. After this procedure, the slides were thoroughly rinsed in distilled water, toned in 0. Bucher proposes that habitat modification by livestock grazing favours establishment of vizcachas. Variations in the amount of pineal pigments related to serum hormone levels were crespl between pregnant and nonpregnant viscachas.
The pinealocyte exhibited a large amount of mitochondria in the cytoplasm. Endocrinology and Metabolismvol. Immunohistochemical scoring was determined using a 4-point scale: Forbs, scarce vizccaha La Payunia, constituted seasonal dietary elements. This process of melanin transference has already been suggested in cat [ 18 ] and bat [ 16 ]. Estradiol and progesterone serum levels were determined by RIA. View at Google Scholar V. Conflicts of Interest The authors declare that there is no conflict of interests crdspo the publication of this paper.
International Journal of Endocrinology. Effect of pituitary and ovarian hormones on human melanocytes in vitro.
There was a problem providing the content you requested
Journal of the Anatomical Society of India. Specificity of primary antibodies was corroborated in adjacent sections by omission of the primary antibodies. Morphometric Analysis The pigmented cells were counted in pregnant and nonpregnant viscachas. Vizcacheras found in sandstony ravines Llanos and Crespo could refute the — proposed vizcacha’s preference for plains as vrespo from its distribution Weir The sections were examined using an Olympus BX light microscope.
On the mosaic-like design of La Payunia, plains availability could be a limiting factor for vizcachas. Vizioli for his support during the collection of the data, E. Therefore, to have an approximated idea of the PRL production along the reproductive stages of adult female vizcachas, we examined its expression in the pituitary by immunohistochemistry and by qPCR Figure 6.