The timeline development of female canine germ cells.

During the sex differentiation, the primordial germ cells (PGCs) pass through a differentiation, becoming spermatogonial cells in males and oocytes in females. In this phase, there is difference in gene expression and differentiation potency between males and females. Specific cell markers have been essential in the PGC meiosis beginning and become oocyte cells. However, there are few studies about germline in domestic animals. The domestic dog (Canis lupus familiaris) is an interesting animal model to be used in the investigation about the mammal development because it has several biochemical and physiological similarities to humans. In addition, some additional investigations about dogs may contribute to a better understanding of the biology and genetic components, improving clinical veterinary and zoological sciences. Here, we elucidated by immunofluorescence and quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR), the dynamics of the expression of pluripotent (POU5F1 and NANOG) and germline (DDX4, DAZL and DPPA3) markers that are very important in the development of female canine germ cells during 35-50 days post-fertilization (dpf). The female canine germ cells were positive for pluripotent markers during middle developmental period. The number of DDX4, DAZL and DPPA3 cells increased along the germ cell maturation from 45 to 50 dpf. We provided an expression analysis of the pluripotent and germline markers in paraffin sections using the middle and later periods in female canine germ cells. The results can contribute the understanding about the timeline of each marker along the maturation of female canine germ cells. These results have a great significance to demonstrate the germ cell profile changes because it may allow the development of protocols about in vitro germ cell derivation.

Evaluation of the applicability of musculoskeletal ultrasonography of the thoracolumbar and lumbar spine segment of healthy dogs / Avaliação da aplicabilidade da ultrassonografia musculoesquelética do segmento toracolombar e lombar da coluna vertebral de cães hígidos

Changes in the spine of dogs are usually detected in clinical and in surgical practice. Few studies exist on musculoskeletal ultrasound anatomy of the thoracolumbar and lumbar segments of the normal spine of dogs. This study aimed to compare the normal musculoskeletal ultrasound anatomy of the T10-S1 vertebral segments with images obtained with magnetic resonance imaging (MRI), computed tomography (CT), and anatomical structures, and to establish the ability to identify structures using these modalities. Ultrasound scans allowed visualization of the muscles of the region, articular processes, spinous process, interspinous ligament, and yellow ligament in the lumbosacral window. Computed tomography images provided better bone details, compared to ultrasound images. Low-field MRI allowed the identification of the same structures identified with ultrasound imaging, and allowed the identification of cerebrospinal fluid, transverse processes, and provided improved detail of the intervertebral discs and spinal cord. Knowledge of ultrasound anatomy of the region may allow the the identification of muscle and ligament injuries. Thus, in cities where CT and MRI are inaccessible, ultrasonography of the region could be a good alternative to identify possible changes not observable with radiographic examination or to complement radiographic examination.(AU)

Alterações na coluna vertebral de cães são comumente encontradas na rotina clínica e cirúrgica veterinária. Existem poucos estudos sobre a anatomia ultrassonográfica musculoesquelética do segmento toracolombar e lombar da coluna vertebral normal de cães. O objetivo deste trabalho foi comparar a anatomia ultrassonográfica musculoesquelética normal dos segmentos vertebrais T10-S1 com imagens obtidas pela ressonância magnética, tomografia computadorizada e peças anatômicas visando demonstrar a sua capacidade de identificação de estruturas. A varredura ultrassonográfica permitiu a visibilização da musculatura da região, processos articulares, processos espinhosos, ligamentos interespinhosos e ligamento amarelo na janela lombossacra. A tomografia computadorizada forneceu imagens com melhor detalhamento ósseo quando comparada ao exame ultrassonográfico. A ressonância magnética de baixo campo permitiu a identificação das mesmas estruturas que o exame ultrassonográfico acrescido da identificação do líquido cerebroespinal, processos transversos e melhor detalhamento dos discos intervertebrais e medula espinhal. Com o conhecimento da anatomia ultrassonográfica da região, acredita-se que lesões musculares e ligamentares possam ser identificadas. Vale salientar que em cidades onde a tomografia computadorizada e a ressonância magnética não estejam acessíveis a ultrassonografia da região pode ser uma boa alternativa para identificar possíveis alterações não visibilizadas ao exame radiográfico, ou complementá-lo.(AU)