| synaptonemal complex analysis of spermatocytes of talpa occidentalis (insectivora, mammalia): autosomal synapsis and substaging of zygonema and pachynema. | spermatocytes from the mole, talpa occidentalis, a species that includes both xx males and intersexes, were surface-spread and silver-stained to substage meiotic prophase from early zygonema through pachynema. in zygonema, only the z2 and z3 substages were found. this stage differed in comparison with such species as the chinese hamster, laboratory mouse, and deer mouse, which belong to orders other than insectivora. pachynema, in which five substages were established (p1-p5), seems to be a more ... | 1990 | 2369848 |
| descriptive kinetics of the seminiferous epithelium cycle and genome size in the mole talpa occidentalis (insectivora). | the male germ cell cytodifferentiative process of the mole talpa occidentalis is described. cytochemical procedures were used 1) to follow acrosome formation and spermatid differentiation, dividing the seminiferous epithelium cycle into ten stages, each characterized by typical germ cell-to-cell associations, and recognizing 13 steps in spermatid differentiation; 2) to monitor, in situ, histones replacement by protamines at step 11 of the spermiogenic process. the seminiferous epithelium cycle o ... | 1995 | 7561724 |
| abnormal sex-duct development in female moles: the role of anti-müllerian hormone and testosterone. | we have performed a morphological, hormonal and molecular study of the development of the sex ducts in the mole talpa occidentalis. females develop bilateral ovotestes with a functional ovarian portion and disgenic testicular tissue. the müllerian ducts develop normally in females and their regression is very fast in males, suggesting a powerful action of the anti-müllerian hormone in the mole. rt-pcr demonstrated that the gene governing this hormone begins to be expressed in males coinciding wi ... | 2003 | 14584782 |
| the molecular basis of defective lens development in the iberian mole. | fossorial mammals face natural selection pressures that differ from those acting on surface dwelling animals, and these may lead to reduced visual system development. we have studied eye development in a species of true mole, the iberian mole talpa occidentalis, and present the molecular basis of abnormal lens development. this is the first embryological developmental study of the eyes of any fossorial mammal at the molecular level. | 2008 | 18939978 |
| the spatio-temporal pattern of testis organogenesis in mammals - insights from the mole. | some cellular events are crucial in testis organogenesis, including sertoli and leydig cell differentiation, mesonephric cell migration and testis cord formation. these processes are controlled by transcription factors, paracrine signalling and hormones. using the mole species talpa occidentalis as an alternative animal model, we report the expression patterns of nine genes during testis differentiation and analyse their implications in the above-mentioned cellular processes. we show that: 1) se ... | 2009 | 19598120 |
| development of the cornea of true moles (talpidae): morphogenesis and expression of pax6 and cytokeratins. | corneal development and structure were studied in the iberian mole talpa occidentalis, which has permanently closed eyelids, and the european mole talpa europaea, in which the eyes are open. the vertebrate cornea typically maintains a three-layered structure - a stratified epithelium with protective and sensory function, an avascular, hypocellular, collagenous stroma, and an endothelium with both barrier and transport functions that regulates corneal hydration, hence maintaining transparency. co ... | 2010 | 20979588 |
| the placentation of eulipotyphla-reconstructing a morphotype of the mammalian placenta. | placentation determines the developmental status of the neonate, which can be considered as the most vulnerable stage in the mammalian life cycle. in this respect, the different evolutionary and ecological adaptations of marsupial and placental mammals have most likely been associated with the different reproductive strategies of the two therian clades. the morphotypes of marsupial and placental neonates, as well as the placental stem species pattern of marsupialia, have already been reconstruct ... | 2014 | 24797275 |
| pattern and density of vascularization in mammalian testes, ovaries, and ovotestes. | according to the classical paradigm, the vasculature of the embryonic testis is more dense and complex than that of the ovary, but recent studies based on whole-mount detection of caveolin-1 (cav1) as an endothelial cell marker, have suggested that the level of ovarian vascularization is higher than previously assumed. however, this new hypothesis has been neither tested using alternative methodology nor investigated in other mammalian species. in this paper, we have studied the vascularization ... | 2012 | 22544714 |
| genetic diversity of talpa europaea and nova hanta virus (nvav) in france. | nova hantavirus (nvav) was first identified in a single european mole (talpa europaea), captured in hungary. analysis of lung tissues from 94 moles captured in france revealed nvav in 50%. based on the genetic diversity of the cytochrome b mtdna, moles collected in poitiers and bordeaux were more closely related to the iberian mole (t. occidentalis), a species previously assumed to be restricted to the iberian peninsula. several hypotheses are discussed to explain these observations: 1) presence ... | 2014 | 25530620 |
| complete mitochondrial genome of the iberian mole talpa occidentalis (talpidae, insectivora) and comparison with talpa europaea. | the complete mitogenome of talpa occidentalis, the iberian mole, was sequenced using a combination of the illumina and sanger methods. the 16,962 bp genome obtained contains 13 protein-coding genes, 22 transfer rnas, 2 ribosomal rnas, and a control region. thirty-seven identical repetitions of a 10-nucleotide (cacacgtacg) repeat element were identified in the non-coding control region (d-loop). the number, order, and orientation of the mitochondrial genes are the same as in t. europaea, the only ... | 2018 | 30145730 |
| first finding of ityogonimus lorum and i. ocreatus co-infection in the iberian mole, talpa occidentalis. | the ityogonimus lorum-i. ocreatus co-infection is reported for the first time in the iberian mole talpa occidentalis in asturias (nw spain). both ityogonimus species are stenoxenous helminths of insectivores of the genus talpa and they have often been found parasitizing the iberian mole and also the european mole t. europaea, but a mixed infection had not been previously reported. the present study also highlights the main differential morphometric characteristics between i. lorum and i. ocreatu ... | 2018 | 30367768 |
| testis-like development of gonads in female moles. new insights on mammalian gonad organogenesis. | moles are unique among mammals because all females of several species of genus talpa have bilateral ovotestes (gonads with both ovarian and testicular tissue). based on the analysis of a large sample of embryos, foetuses and infants over a 13-year period, we have studied the development of the gonads in male and female moles of the species talpa occidentalis. several new field and laboratory procedures were developed specifically to obtain and manage this singular material. our results reveal th ... | 2004 | 15031103 |
| retinal development and function in a 'blind' mole. | animals adapted to dark ecotopes may experience selective pressure for retinal reduction. no previous studies have explicitly addressed the molecular basis of retinal development in any fossorial mammal. we studied retinal development and function in the iberian mole talpa occidentalis, which was presumed to be blind because of its permanently closed eyes. prenatal retina development was relatively normal, with specification of all cell types and evidence of dorsoventral regionalization. severe ... | 2010 | 20007180 |
| identification of live germ-cell desquamation as a major mechanism of seasonal testis regression in mammals: a study in the iberian mole (talpa occidentalis). | in males of seasonally breeding species, testes undergo a severe involution at the end of the breeding season, with a major volume decrease due to massive germ-cell depletion associated with photoperiod-dependent reduced levels of testosterone and gonadotropins. although it has been repeatedly suggested that apoptosis is the principal effector of testicular regression in vertebrates, recent studies do not support this hypothesis in some mammals. the purpose of our work is to discover alternative ... | 2013 | 23515671 |
| morphology and ultrastructure of the chorioallantoic placenta of the iberian mole (talpa occidentalis) with special reference to heterophagous areolas and the nature of interhaemal barrier. | this study provides a contribution to the reconstruction of the eulipotyphlan placental morphotype and also may help resolving a long-standing conflict about the interhaemal barrier in moles. as detailed descriptions of talpid placentation, only available for talpa europaea and scalopus aquaticus, led to a controversial debate on the nature of interhaemal barrier, the collection of more placental data of further mole species was strongly desired. hence, the placentas of six gestational stages of ... | 2012 | 22703538 |
| circumventing the polydactyly 'constraint': the mole's 'thumb'. | talpid moles across all northern continents exhibit a remarkably large, sickle-like radial sesamoid bone anterior to their five digits, always coupled with a smaller tibial sesamoid bone. a possible developmental mechanism behind this phenomenon was revealed using molecular markers during limb development in the iberian mole (talpa occidentalis) and a shrew (cryptotis parva), as shrews represent the closest relatives of moles but do not show these conspicuous elements. the mole's radial sesamoid ... | 2012 | 21752813 |
| circannual testis changes in seasonally breeding mammals. | in the non-equatorial zones of the earth, species concentrate their reproductive effort in the more favorable season. a consequence of seasonal breeding is seasonal testis regression, which implies the depletion of the germinative epithelium, permeation of the blood-testis barrier, and reduced androgenic function. this process has been studied in a number of vertebrates, but the mechanisms controlling it are not yet well understood. apoptosis was assumed for years to be an important effector of ... | 2015 | 26375035 |
| transcriptional heterochrony in talpid mole autopods. | talpid moles show many specializations in their adult skeleton linked to fossoriality, including enlarged hands when compared to the feet. heterochrony in developmental mechanisms is hypothesized to account for morphological evolution in skeletal elements. | 2012 | 22873211 |
| hox gene expression in the specialized limbs of the iberian mole (talpa occidentalis). | fossorial talpid moles use their limbs predominantly for digging, which explains their highly specialized anatomy. the humerus is particularly short and dorsoventrally rotated, with broadened distal and proximal parts where muscles attach and which facilitate powerful abductive movements. the radius and ulna are exceptionally robust and short. the ulna has an expanded olecranon process. the femur is generalized, but the fused tibia-fibula complex is short and robust. to understand the developmen ... | 2017 | 28058796 |
| synaptonemal complex analysis in talpa occidentalis spermatocytes (insectivora, mammalia). ii. evolution of the x-chromosome self-pairing process. | zygotene and pachytene configurations of the x chromosome were studied in whole-mount, silver-stained preparations of spermatocytes from xy males from a population of talpa occidentalis in which sex reversal has been described. the most striking finding in this study was a self-pairing conformation of the axial (differential) element of the x chromosome. this self-pairing was markedly constant in the site of initiation, which invariably involved the distal free end of the x and the region beyond ... | 1990 | 2249472 |
| fertile females of the mole talpa occidentalis are phenotypic intersexes with ovotestes. | we investigated the origin of xx sex reversal in the insectivorous mole talpa occidentalis. cytogenetic, histological and hormonal studies indicate that all xx individuals analyzed from two different populations are true hermaphrodites, with ovotestes. this suggests that xx sex reversal may be the norm in this species. the intersexes are functional fertile females and the trait is transmitted and maintained in the population. intersexes lack the y chromosome gene sry (sex determining region y ge ... | 1993 | 8269856 |
| ovotestis variability in young and adult females of the mole talpa occidentalis (insectivora, mammalia). | the age-related evolution and ontogenic origin of the ovotestes in fertile females of the spanish mole (talpa occidentalis) were studied. volume of the ovotestis and its ovarian and testicular components, size of the epididymis and testicular cords, number of ovarian follicles and testicular cords, uterus weight, and age index were analyzed statistically in a large sample of young and adult individuals of this species. comparison of means and linear correlation analyses were done. most variables ... | 1996 | 8742693 |
| interchromosomal, intercellular and interindividual variability of nors studied with silver staining and in situ hybridization. | we investigated the relationship between transcriptional activity and the quantity of ribosomal cistrons of the nucleolar organizing regions (nors) in chromosomal pair 3 of the spanish mole talpa occidentalis. transcriptional activity was estimated by the size of conventional silver-staining signals. the number of ribosomal cistrons was estimated by the size of the in situ hybridization signals obtained with a ribosomal dna probe. a sample of cells was studied with each method in four different ... | 1997 | 9119702 |
| sequential silver staining and in situ hybridization reveal a direct association between rdna levels and the expression of homologous nucleolar organizing regions: a hypothesis for nor structure and function. | we have developed a procedure for sequential silver staining and in situ hybridization to analyze the relationship between the amount of rdna present in nucleolar organizer regions, as estimated by in situ hybridization, and their level of expression, as estimated by the silver signal. for simplicity we used cells from the insectivorous mole talpa occidentalis, which have a single pair of nucleolar organizer regions in chromosome pair 3. the relative content of ribosomal cistrons was also relate ... | 1998 | 9570760 |
| role of apoptosis and cell proliferation in the testicular dynamics of seasonal breeding mammals: a study in the iberian mole, talpa occidentalis. | apoptosis and cell proliferation are two important cellular processes known to be involved in the normal functioning of the testis in nonseasonally breeding mammals, but there is some controversy concerning their roles in the gonads of males from seasonally breeding species. we have studied the processes of apoptosis and cell proliferation in the testes of males of the iberian mole (talpa occidentalis), a species showing a strict seasonal reproduction pattern. both males and females are sexually ... | 2010 | 20357272 |
| expression of genes controlling testicular development in adult testis of the seasonally breeding iberian mole. | most testicular features undergo major circannual variation in seasonal breeding species. although the ultimate cause of these variations is known to be the photoperiod in most cases, very little is known about the genetic mechanisms by which these changes are modulated in the testis. many genes involved in testis development are known to be expressed in the adult testis as well. since these genes encode genetic regulatory factors, it is reasonable to suspect that they could play some role in th ... | 2011 | 21412037 |
| the mole genome reveals regulatory rearrangements associated with adaptive intersexuality. | linking genomic variation to phenotypical traits remains a major challenge in evolutionary genetics. in this study, we use phylogenomic strategies to investigate a distinctive trait among mammals: the development of masculinizing ovotestes in female moles. by combining a chromosome-scale genome assembly of the iberian mole, talpa occidentalis, with transcriptomic, epigenetic, and chromatin interaction datasets, we identify rearrangements altering the regulatory landscape of genes with distinct g ... | 2020 | 33033216 |
| ultrastructure and cytochemistry of intrauterine embryonic and larval stages of ityogonimus lorum (digenea: brachylaimidae) involving transitory development of ciliated miracidia. | results of the present study provide ultrastructural evidence that miracidial morphogenesis is fully completed within the intrauterine eggs while in the most posterior uterine regions of ityogonimus lorum, a digenean parasite of an iberian mole, talpa occidentalis (eulipotyphla, talpidae). using transmission electron microscopy (tem), the ultrastructural characteristics of diverse cell types and their organelles of these developing embryos and fully formed miracidia within the eggshell were exam ... | 2020 | 32107619 |
| mercury, lead and cadmium concentrations in talpa occidentalis and in their digeneans of the genus ityogonimus. | many parasites living in aquatic ecosystems are useful indicators of environmental health. on the other hand, information is scarcer with respect to the use of helminth parasites of vertebrates living in terrestrial ecosystems as monitoring tools for toxic element environmental pollution. the present study evaluates the suitability of the model talpa occidentalis/ityogonimus spp. as a bioindicator system for mercury (hg), lead (pb) and cadmium (cd) contamination in agricultural soils from asturi ... | 2019 | 31165991 |
| soboliphyme occidentalis sp. nov. (nematoda, soboliphymidae) from the iberian mole talpa occidentalis (insectivora, talpidae) in spain. | a new species of soboliphyme from the endemic iberian mole (talpa occidentalis) is described. soboliphyme occidentalis sp. nov. can be readily distinguished from all of its congeners primarily by the position of the vulva, which clearly shows a posterior oesophageal location, and the number of male caudal papillae. s. occidentalis sp. nov. is the only species that has four pairs of caudal papillae. s. abei, s. caucasica and s. jamesoni can be distinguished from s. occidentalis sp. nov. by not ha ... | 2004 | 15278444 |