Distribution of commensal rodents in rain-fed and irrigated areas of Swat district, Khyber Pakhtunkhwa, Pakistan / Distribuição de roedores comensais em áreas irrigadas e chuvosas do distrito de Swat, Khyber Pakhtunkhwa, Paquistão

Distribution pattern and relative abundance of the agricultural rodent pests of rain-fed and irrigated areas of district Swat Khyber Pakhtunkhwa, Pakistan were recorded from April 2011 to November 2013 using wire mesh live traps. A total of 350 rodents (269 Rattus rattus and 81 Mus musculus) were captured under 2268 trap nights (trap success: 0.15). Regression of daily captures on cumulative captures revealed an estimate of 350 rodents from all the sampled structures with an average of 21.8 rodents per crop field. House rats (R. rattus; 76.8% of captures) were numerically dominant in almost all types of agricultural fields, and were significantly different from the mice (Mus musculus; 23.1% of captures). Both species were found together in some fields. The sex ratio revealed that males outnumbered the females in both of the reported species.

O padrão de distribuição e a abundância relativa de pragas de roedores agrícolas nas áreas irrigadas e irrigadas do distrito Swat Khyber Pakhtunkhwa, Paquistão foram registrados de abril de 2011 a novembro de 2013 usando armadilhas vivas de malha de arame. Um total de 350 roedores (269 Rattus rattus e 81 Mus musculus) foram capturados em 2268 noites de armadilha (sucesso da armadilha: 0,15). A regressão das capturas diárias em capturas cumulativas revelou uma estimativa de 350 roedores de todas as estruturas amostradas, com uma média de 21,8 roedores por campo agrícola. Os ratos domésticos (R. rattus; 76,8% das capturas) foram numericamente dominantes em quase todos os tipos de campos agrícolas e foram significativamente diferentes dos camundongos (Mus musculus; 23,1% das capturas). Ambas as espécies foram encontradas juntas em alguns campos. A proporção de sexo revelou que os machos superaram as fêmeas em ambas as espécies relatadas.

Distribution of commensal rodents insome shops of three districts in Malakand region, Pakistan / Distribuição de roedores comensais em algumas lojas de três distritos na região de Malakand, Paquistão

Using wire mesh live traps distribution pattern of the Rattus rattus and Mus musculus in different shops of three districts of Malakand region, Pakistan were recorded from September 2014 to October 2015. Over all 103 rodents (Rattus rattus 86 and Mus musculus 17) were caught during in 0.04 trap success (2448 trap nights). Regression of daily captures on cumulative captures revealed an estimate of 103 rodents from all the sampled structures with an average of 3.55 rodents per shop. R. rattus; 83.4% of captures were numerically dominant in almost all types of shops sampled, and were significantly different than Mus musculus; 16.5% of captures. Both species were found together in some shops while they were mostly trapped from the separate shops. Male rodents outnumbered the females.

Usando o padrão de distribuição de armadilhas vivas de malha de arame do Rattus rattus e Mus musculus em diferentes lojas de três distritos da região de Malakand, o Paquistão foi registrado de setembro de 2014 a outubro de 2015. No total, 103 roedores (Rattus rattus 86 e Mus musculus 17) foram pegos durante em 0,04 armadilha de sucesso (2448 noites de armadilha). A regressão das capturas diárias em capturas cumulativas revelou uma estimativa de 103 roedores de todas as estruturas amostradas, com uma média de 3,55 roedores por loja. R. rattus; 83,4% das capturas foram numericamente dominantes em quase todos os tipos de lojas da amostra e foram significativamente diferentes do Mus musculus; 16,5% das capturas. Ambas as espécies foram encontradas juntas em algumas lojas, enquanto estavam na maior parte presas em lojas separadas. Os roedores machos eram mais numerosos do que as fêmeas.

Esqueletogênese em punaré (Thrichomys laurentinus- Rodentia, Echimyidae) / Skeletogenesis in punare (Thrichomys laurentinus - Rodentia, Echimyidae)

O objetivo deste estudo foi descrever o desenvolvimento do esqueleto do punaré (Thrichomys laurentinus). Para tanto, foram utilizados 11 embriões e 12 fetos em diferentes estágios de desenvolvimento, sendo divididos em 4 grupos de acordo com o período gestacional. As amostras foram obtidas no Centro de Multiplicação de Animais Silvestres da Universidade Federal Rural do Semi-Árido, Mossoró-RN, Brasil. Após fixados em formol (10%) ou glutaraldeído (2,5%), foi realizada a analise morfológica com auxílio de lupa, sendo as características macroscópicas fotodocumentadas. Análises de raios-x e coloração por alizarina red foram realizadas para melhor compreensão do desenvolvimento ósseo. Nas análises de raio-x os embriões não apresentaram nenhuma radiopacidade, ao contrário dos fetos que apresentavam radiopacidade gradual ao longo dos grupos. No grupo II houve aumento de radiopacidade na região da coluna vertebral e das regiões mandibular e maxilar. No grupo III a radiopacidade estava aumentada nos membros pélvicos, nas costelas e na região frontal e no grupo IV nos membros torácicos e nas regiões occipital, temporal e frontal do crânio. Tais características foram confirmadas pelas analises histológicas e pela técnica de Alizarina Red. Com isso podemos concluir que o conhecimento acerca da embriologia do sistema ósseo normal é fundamental para o entendimento dos efeitos adversos causados pela nutrição e uso de drogas durante o desenvolvimento.(AU)

The aim of this study was to describe the skeletogenesis in punaré (Thrichomys laurentinus). We used 11 embryos and 12 fetuses in different stages of development, allocated into 4 groups. Samples were obtained from the Multiplication Center of Wild Animals, at Federal Rural University of the Semi-Arid, Mossoro/RN, Brazil. After fixed in formalin (10%) or glutaraldehyde (2.5%) the morphological analysis was performed with a magnifying glass, and the macroscopic characteristics were photographed. Analysis of X-rays and alizarin red staining was made to better understand the development of bone structures. In x-ray analysis, it was possible to verify that the embryos showed no radiopacity, unlike fetuses that had gradual radiopacity along of the groups. In group II, there was an increase in radiopacity in the spine, mandibular and maxillary regions. In group III, the radiopacity was increased in the hind limbs, ribs and in the frontal region, and group IV showed higher radiopacity in the thoracic limbs and occipital, temporal and frontal skull. These characteristics were confirmed by histological and alizarin red analysis. We concluded that the knowledge of normal skeletal embryology is critical for understanding of adverse effects caused by nutrition and use of drugs during the development.(AU)

A microestrutura e o desenvolvimento dos órgãos genitais masculinos de preás (Galea spixii) criados em cativeiro / The microstructure and development of male genital organs of Spix's yellow-toothed cavy (Galea spixii) bred in captivity

O preá do semiárido nordestino (Galea spixii) é um roedor pertencente à família Caviidae. São encontrados nas regiões da Caatinga e do Cerrado Brasileiro e se reproduz ao longo do ano, apresentando um período de gestação de 48 dias e uma ninhada de 2 a 4 crias. O objetivo deste estudo foi caracterizar histologicamente os componentes estruturais dos órgãos genitais de preás machos relacionando com a evolução cronológica destes órgãos na espécie. Foram utilizados para análise animais ao nascimento e aos 15, 30, 45, 60, 75, 90, 105, 120 e aos 150 dias de idade. Fragmentos do epidídimo, ducto deferente, pênis e glândulas sexuais acessórias foram coletados, fixados e processados para descrição em microscopia de luz. O epidídimo apresentou epitélio colunar simples e em cada fase sexual notou-se diferença quanto ao tamanho do lúmen tubular e à presença de espermatozóides no lúmen aos 45 dias de idade. O epitélio do ducto deferente no preá mostrou-se pseudo-estratificado colunar com crescente presença de estereocilios com o avanço da idade. A glândula vesicular no preá apresentou uma mucosa com pregueamento variado, de acordo com a fase do desenvolvimento sexual. A próstata mostrou-se pouco desenvolvida, com lúmen pequeno nos preás ao nascimento e aos 15 dias de idade; aos 45 dias mostrou-se com um pregueamento do epitélio variável. Os órgãos genitais masculinos do preá passaram por transformações morfológicas no decorrer da idade e com o desenvolvimento sexual, isso colaborou para a determinação do início da fase da puberdade, que na espécie em estudo foi aos 45 dias de idade.(AU)

The Spix's yellow-toothed cavy (Galea spixii) from the Brazilian northeastern semi-arid is a rodent that does belong to the family Caviidae. They are found in regions of the Caatinga and Cerrado, and reproduces throughout the year, with a gestation period of 48 days and a litter of 2 to 4 pups. The aim of this study was to characterize histologically the structural components of the genital organs of male Spix's yellow-toothed cavies regarding their chronological development. For the analysis we used animals at birth and with 15, 30, 45, 60, 75, 90, 105, 120 and 150 days of age. Fragments of the epididymis, vas deferens, penis and accessory sex glands were collected, fixed and processed for light microscopic. The epididymis had a simple columnar epithelium and at each sexual stage the epididymis was noted different in size of the tubular lumen and regarding the presence of sperm in the lumen at 45 days of age. The epithelium of vas deferens was found to be pseudo-stratified columnar with increasing presence of stereocilia with advancing age. The vesicular gland showed a folded mucosa that varied according to stage of sexual development. The prostate was not very developed, with a small lumen in Spix's yellow-toothed cavy at birth and at 15 days of age; at 45 days showed variable wrinkling of the epithelium. The male genital organs underwent morphological transformations in line with age and sexual development, what helped to determine the onset of puberty, which in the species studied occurred at 45 days of age.(AU)

Character transformations and their functional significance as a key to the evolution of hystricognath Rodentia

Hystricognathi represent a monophyletic taxon within Rodentia. Since phylogenetically analyzed morphological systems are essential for revealing evolutionary processes, this study identifies evolutionary character transformations on the stem lineage of Hystricognathi as derived from the author's own work and the literature. Data so far indicate that evolutionary transformations in the rostral head region, the loss of tactile ability in the outer nasal skin and the mobile arrangement of the associated cartilage, were allied with a switch from omnivorous to herbivorous and fiber-rich nutrition. Additional character transformations in the skull assist in digesting such food. Structures associated with reproduction and placentation show a remarkable pro portion of derived character conditions: the chorioallantoic placenta has a ring-shaped organization and growth structure which optimizes the capacity for passive diffusion, a subplacenta occurred as a specialized region responsible for placental invasion and the inverted yolk sac facilitates substance exchange with the main placenta. Finally, precocial newborns evolved as a derived condition within Rodentia. All things considered, a mode of reproduction is indicated, which does not demand excessive additional energy intake by the mother and is in accordance with her low energetic diet. Hystricognathi possess major character transformations that represent prerequisites for their successful radiation at the time when more open ecosystems and grasslands evolved during Earth history. The analysis resulted in the reconstruction of a life-near picture of the hystricognath stem species pattern with high explanatory power in terms of changes in space and time and their interdependence with biodiversity.

The ovary of Lagostomus maximus (Mammalia, Rodentia): an analysis by confocal microscopy

Lagostomus maximus is a notable mammalian model for reproductive studies. Females have an extremely high ovulation rate, which is due to down-regulation of the follicular apoptosis pathway, which ensures a large pool of developing follicles. This large pool is supported by the convoluted anatomy of the mature ovary, whose germinal tissue is found in irregularly curved ridges throughout the cortex. Medullary tissue is restricted to a minimum. Lyso Tracker Red reconstruction under confocal laser scanning microscopy was used to recognize and measure all follicular stages from primordial to antral. Unlike most mammals in which early primordial follicles are just found in fetal life, the adult ovary shows regions packed with early primordial follicles. Follicle size ranged from 24 to 316 µm. We discuss the relationships of L. maximus follicles size with regard to other species of mammals and propose that the physiology of the adult viscacha ovary obeys to a neoteny process in the evolution of this species.

Efecto de la concentración de crioprotectores sobre la viabilidad post vitrificación de embriones murinos (mus musculus) / Effect of cryoprotectant concentration on the post vitrification morphological viability of murine embryos (mus musculus)

Con la finalidad de determinar la mejor solución de vitrificación (SV), usando Etilenglicol (EG), Glicerol (G) y Sucrosa (SUC), se evaluó la apariencia morfológica post vitrificación de embriones murinos (Mus musculus). Ocho mezclas diferentes de crioprotectores fueron evaluadas, con las siguientes concentraciones: SV1: 0% de crioprotectores; SV2: 50% EG; SV3: 50% G; SV4: 50% SUC; SV5: 25% EG + 25% G; SV6: 50% EG + 0,3M SUC; SV7: 50% G + 0.3M SUC y SV8: 25% EG + 25% G + 0,3M SUC. El mayor número de embriones (94,7%) con apariencia morfológica normal, fueron los equilibrados con SV5. No hubo diferencia significativa entre la SV8 (88,9%) y la SV5. Mientras que los embriones criopreservados con las soluciones restantes, presentaron viabilidad morfológica más baja (p<0,05). Estos resultados sugieren que la SV5 provee mejor tolerancia al proceso de vitrificación, observándose en los embriones la más alta viabilidad y la más baja frecuencia de anormalidades morfológicas. Estos hallazgos contribuyen de manera importante, en la selección de los crioprotectores para la vitrificación.

In order to determine the best vitrification solution (VS), using ethylene glycol (EG), glycerol (G) and sucrose (SUC), the post vitrification morphology in murine embryos (Mus musculus) was evaluated. Eight different mixtures of these chemicals, with the following concentrations: VS1: 0%; VS2: 50% EG; VS3: 50% G; VS4: 50% SUC; VS5: 25% EG + 25% G; VS6: 50% EG + 0.3M SUC; VS7: 50% G + 0.3M SUC and SV8: 25% EG + 25% G + 0.3M SUC, were used. VS5 was the solution with the highest percentage (94,7%) of embryos with normal morphology. There were no significant differences between the VS8 (88.9%) and VS5. However, embryos cryopreserved with the other solutions had a lower morphological viability (p<0.05). These results suggest that VS5 provides embryos with better tolerance to the vitrification process, because a higher viability and lower frequency of morphological abnormalities were present. These findings provide details of great importance to the selection of cryoprotectants for vitrification.

Densidad neuronal en la corteza visual primaria (area 17(, de dos especies de roedores silvestres / Neuronal density in primary visual cortex (17 visual area), in two wild rodent species

Diversos estudios experimentales demuestran que modificaciones medioambientales (por ejemplo: nutricionales y lumínicas), pueden producir alteraciones en el desarrollo normal de la corteza visual y sus conexiones. Por otro lado, es posible que en condiciones naturales, las especies animales hayan desarrollado adaptaciones a las distintas condiciones de luminosidad en que realizan su actividad. Por ende, la finalidad de este trabajo, fue estudiar la corteza visual primaria (área 17), de dos especies de roedores silvestres, relacionados filogenéticamente, pero con diferentes períodos de actividad; Abrothrix olivaceus (n=7) y Phyllotis darwini (n=7), con el propósito de evidenciar cambios detectados a través de la medición de la densidad neuronal, mediante la técnica del disector óptico, en cortes de 40µm de grosor, incluidos en celoidina y teñidos con cresyl violeta (Nissl). A. olivaceus, el cual presenta un periodo de actividad continuo en la zona central de Chile, evidenció una densidad neuronal menor (34.75 x 104 ± 1.35 x 104 neuronas/mm3) que la observada en P. darwini (37.23 x 104 ± 2.20 x 104 neuronas/mm3), especie de actividad nocturna en la misma región del país; siendo lo anterior estadísticamente significativo (t=2.54; p<0.05). Las diferencias encontradas se relacionarían con el tipo de conducta que presentan ambas especies, dado principalmente por las características de luminosidad en que se desenvuelven, así como también, de otros factores que se relacionarían con este parámetro, como son la relación predador-presa y la alimentación, entre otros.