Identification of hepatic progenitor cells in the canine fetal liver.

The liver plays essential roles in human and animal organisms, such as the storage, release, metabolism, and elimination of various endogenous or exogenous substances. Although its vital importance, few treatments are yet available when a hepatic failure occurs, and hence, the use of stem cells has arisen as a possible solution for both human and veterinary medicines. Previous studies have shown the existence of hepatic progenitor cells in human fetuses that were positive for EpCAM and NCAM. There is limited evidence, however, further identification and characterization of these cells in other species. Considering the similarity between dogs and humans regarding physiology, and also the increasing importance of developing new treatments for both veterinary and translational medicine, this study attempted to identify hepatic progenitor cells in canine fetal liver. For that, livers from canine fetuses were collected, cells were isolated by enzymatic digestion and cultured. Cells were characterized regarding morphology and expression of EpCAM, NCAM, Nestin, and Thy-1/CD90 markers. Our results suggest that it is possible to identify hepatic progenitor cells in the canine fetal liver; however, for therapeutic use, further techniques for cellular isolation and culture are necessary to obtain enriched populations of hepatic progenitors from the canine fetal liver.

Selection of strawberry cultivars with tolerance to Tetranychus urticae (Acari: Tetranychidae) and high yield under different managements.

Tetranychus urticae Koch (Acari: Tetranychidae) is considered the main pest of strawberry. Several factors can favor its development, among them the genotype susceptibility and cropping system. The aims of this study were to evaluate the agronomic performance of strawberry cultivars under different managements and to identify strawberry cultivars that meet tolerance to T. urticae and high fruit yield. Thirteen cultivars of strawberry ('Albion', 'Aleluia', 'Aromas', 'Camarosa', 'Camino Real', 'Campinas', 'Diamante', 'Dover', 'Festival', 'Seascape', 'Toyonoka', 'Tudla', and 'Ventana') under three managements (open field, low tunnel, and high tunnel) were evaluated. The T. urticae attack to different cultivars was influenced by managements, being low tunnel the one that provided higher infestations in the most evaluated cultivars. 'Camarosa' was the cultivar with the lower incidence of pest and 'Dover' had the higher infestation. The genotype most suitable for growing under different managements is the 'Festival' genotype, since it meets tolerance to T. urticae, high fruit yield, and phenotypic stability.

Transplantation of amniotic membrane-derived multipotent cells ameliorates and delays the progression of chronic kidney disease in cats.

Chronic kidney disease (CKD) is a common clinical condition in domestic cats, characterized by tubulointerstitial, vascular and glomerular inflammation and severe fibrosis. Studies in rodent model of induced CKD have shown a decrease and stabilization of the clinical condition. In this study was evaluated the safety and effect of intrarenal and intravenous infusion of allogeneic mesenchymal stem cells (AMSCs) derived from feline amniotic membrane in cats with naturally occurring CKD. Cat AMSCs were harvested after mechanical and enzymatic digestion of amnion. A healthy cat received intrarenal injection of AMSCs guided by ultrasound in both kidneys (5 × 105  cells/kidney). Nine cats with CDK received repeated intravenous infusions of AMSCs (2 × 106 cells × 2 treatments). The clinical parameters of healthy cat did not change, but sedation and general anaesthesia was required. The number of interventions stressed the animal, and he developed transient haematuria after AMSC injection. Cats with CDK registered a significant improvement of renal function (decrease in serum creatinine and urine protein concentrations and increase in urine specific gravity). The kidney architecture and morphology did not change following the treatment. The feline AMSCs have a renoprotective effect and improve renal function in cats with naturally occurring CKD, stabilizing the clinical condition and disease progression. Thus, intravenous injection of AMSCs may be an important tool to provide welfare in cats with chronic kidney disease.

Characterization of teratogenic potential and gene expression in canine and feline amniotic membrane-derived stem cells.

The biosafety of innovative procedures that utilize stem cells in regenerative medicine has been addressed in several studies. Previous work has showed no tumour formation following the use of feline and human amniotic membrane-derived stem cells (AMSCs). In contrast, tumour formation was observed when canine AMSCs were utilized. These findings suggested that feline and human, but not canine, AMSCs are suitable for cell transplantation trials. This study aimed to further evaluate the feasibility of utilizing canine AMSCs for transplantation purposes as well as for felines. We tested teratoma formation following cell injection into BALB/c nude mice and then assessed expression of haematopoietic, mesenchymal, tumorigenic, pluripotency and cellular regulation markers using flow cytometry and qPCR. The use of canine AMSCs did not result in macroscopic tumour formation as determined 60 days after transplantation. The immunophenotypic characterization by flow cytometry revealed expression of mesenchymal markers (CD73 and CD90) and expression of the pluripotent marker OCT4 and SOX2. Quantitative PCR analysis revealed that there were no differences in the patterns of gene expression (CD34, CD73, OCT4, CD30 and P53) between canine and feline AMSCs, with the exception of the expression of SOX2 and CD90.

Immunolocalization of proteins in the spermatogenesis process of canine.

Spermatogenesis is a process in which differentiated cells are produced and the adult stem cell population-known as spermatogonial stem cells (SSCs)-is continuously replenished. However, the molecular mechanisms underlying these processes are not fully understood in the canine species. We addressed this in this study by analysing the expression of specific markers in spermatogonia of seminiferous tubules of canine testes. SSCs at different stages of reproductive development (prepubertal and adult) were examined by immunohistochemistry and flow cytometry. Glial cell-derived neurotrophic factor family receptor alpha-1 (GFRA1), deleted in azoospermia-like (DAZL) and promyelocytic leukaemia zinc finger (PLZF) were expressed in SSCs, while stimulated by retinoic acid gene 8 (STRA8) was detected only in undifferentiated spermatogonia in prepubertal testis and differentiated spermatogonia and spermatocytes in adult canine. Octamer-binding transcription factor 4 (OCT4) showed an expression pattern, and the levels did not differ between the groups examined. However, C-kit expression varied as a function of reproductive developmental stage. Our results demonstrate that these proteins play critical roles in the self-renewal and differentiation of SSCs and can serve as markers to identify canine spermatogonia at specific stages of development.

Buffalo (Bubalus bubali) Late Embryo and Foetus Development: A Morphological Analysis.

Many researches describe the embryonic developmental features in domestic animals; however, in farm animals, they are scarce. Most farm animal studies are related to assisted reproduction and embryos transfer techniques. But, morphological features and size measure to estimate the age gestation are rarely reported in literature. Thus, in this study, we described the developmental changes in the bubaline (Bubalus bubali) concepts from 21 to 60 days of gestation. Our results revealed that buffalo embryos similar morphological characteristics similar to other mammalian species. Also, similarities between bovine and bubaline persist; except on foetal stages when buffalos have a faster development than bovine. Therefore, buffalo's gestation period exhibits some varieties and accurate embryo age is more difficult. Yet, when we use a combination of the crown-rump, macroscopic analysis and alizarin red, it is possible to describe better the whole embryogenesis stages of the buffalo and which can contribute for future reproduction researches and applications in veterinary practice.

Comparative Development of Embryonic Age by Organogenesis in Domestic Dogs and Cats.

The precise determination of the embryonic chronology is very important in reproductive biotechnologies, especially in estimating embryonic age. Thus, there is a need for greater knowledge and standardization for determining the chronology of embryonic development and functional morphology. We describe aspects of embryonic development in two domestic carnivores to add knowledge about organ peculiarities and for application in veterinary practice, in prenatal development and in the biotechnology fields. We found that the development of differential characteristics of embryonic organs occurs in the first trimester of pregnancy for both species. Thus, using the combination of the crown-rump length, macroscopic analysis and optical microscopy, it is possible to predict gestational age more precisely in animals that lack a defined breed and establish an embryonic pattern.

Domestic carnivore's development: detection of Oct-4, a pluripotency marker, in pharyngeal arches.

Very few carnivore's embryology is reported mainly restricted to old literature without new technique analyses. Also, their development focuses on pharyngeal arches and stem cell sources and the high capacity for differentiation from those cells to generate embryonic tissue. We aimed to use immunohistochemistry to prove the potentiality of these stem cell niches. The results were to highlight the timetable for the development of dogs and cats, the proper formation of pharyngeal arches and the description of these cells on first and second arches since 17-25 days of pregnancy. After that, the differentiation process is reduced.

Canine fibroblasts expressing human transcription factors: what is in the route for the production of canine induced pluripotent stem cells.

The aim of this study was to further clarify the mechanisms involved in inducing pluripotency using canine foetal fibroblast cells. The two pluripotency-related transcription factors, OCT4 and SOX2, coupled to a fluorescent reporter gene were transduced, individually or in combination, using a lentiviral system. Stable transgenic cell lineages were obtained and canine cells showed to be highly responsive to the integration and expression of human SOX2 and OCT4, also depending on the amount of virus used for incubation. Such positive results are essential for the establishment of pluripotency induction through the incorporation of known transcription factors into the genome of somatic cells.

Chorioallantoic and yolk sac placentation in the plains viscacha (Lagostomus maximus) - a caviomorph rodent with natural polyovulation.

OBJECTIVES: Reproduction in the plains viscacha is characterized by the polyovulation of hundreds of oocytes, the loss of implantation and the development of 1-3 offspring. Our goal was to determine whether placental development was affected by these specializations. STUDY DESIGN: Thirteen placentas from early pregnancy to near-term pregnancy were analyzed using histological, immunohistochemical and transmission electron microscopy. RESULTS: An inverted, villous yolk sac was present. Placentas were formed by the trophospongium, labyrinth and subplacenta. A lobulated structure with a hemomonochorial barrier was established early in pregnancy. Proliferating trophoblast that was clustered at the outer border and inside the labyrinth was responsible for placental growth. Trophoblast invasion resulted from the cellular trophoblast and syncytial streamers derived from the subplacenta. Different from other caviomorphs, numerous giant cells were observed. CONCLUSIONS: The principle processes of placentation in caviomorphs follow an extraordinarily stable pattern that is independent of specializations, such as polyovulation.

Early development and putative primordial germ cells characterization in dogs.

Previously, three distinct populations of putative primordial germ cells (PGCs), namely gonocytes, intermediate cells and pre-spermatogonia, have been described in the human foetal testis. According to our knowledge, these PGCs have not been studied in any other species. The aim of our study was to identify similar PGC populations in canine embryos. First, we develop a protocol for canine embryo isolation. Following our protocol, 15 canine embryos at 21-25 days of pregnancy were isolated by ovaryhysterectomy surgery. Our data indicate that dramatic changes occur in canine embryo development and PGCs specification between 21 to 25 days of gestation. At that moment, only two PGC populations with distinct morphology can be identified by histological analyses. Cell population 1 presented round nuclei with prominent nucleolus and a high nuclear to cytoplasm ratio, showing gonocyte morphology. Cell population 2 was often localized at the periphery of the testicular cords and presented typical features of PGC. Both germ cell populations were positively immunostained with anti-human OCT-4 antibody. However, at day 25, all cells of population 1 reacted positively with OCT-4, whereas in population 2, fewer cells were positive for this marker. These two PGCs populations present morphological features similar to gonocytes and intermediate cells from human foetal testis. It is expected that a population of pre-spermatogonia would be observed at later stages of canine foetus development. We also showed that anti-human OCT-4 antibody can be useful to identify canine PGC in vivo.

Moscas-das-frutas (Diptera: Tephritidae), seus parasitoides e hospedeiros em Viçosa, zona da mata mineira / Fruit flies (Diptera: Tephritidae), their parasitoids and hosts in Viçosa, a forest zone in the state of Minas Gerais, Brazil

Este trabalho apresenta a diversidade de espécies de tefritídeos, seus parasitoides e hospedeiros em Viçosa-MG, localizada na Zona da Mata Mineira. Armadilhas tipo McPhail, contendo proteína hidrolisada, foram instaladas em pomares com espécies diversificadas e em uma reserva natural, remanescente da Mata Atlântica. Além disso foram feitas coletas periódicas de frutos cultivados na região. Foram obtidas 16 espécies de tefritídeos: Ceratitis capitata (Wiedemann), Anastrepha bezzi Lima, A. bistrigata Bezzi, A. dissimilis Stone, A. distincta Greene, A. fraterculus (Wiedemann), A. furcata Lima, A. grandis (Macquart), A. manihoti Lima, A. minensis Lima, A. montei Lima, A. obliqua (Macquart), A. pseudoparallela (Loew), A. pickeli Lima, A. serpentina (Wiedemann) e A. sororcula Zucchi. Destas, apenas C. capitata, A. fraterculus e A. sororcula tinham sido constatadas em Viçosa. A. furcata é registrada pela primeira vez em Minas Gerais. Das 15 espécies frutíferas de seis famílias botânicas amostradas, obtiveram-se C. capitata, A. fraterculus, A. obliqua e A. sororcula e os parasitóides Doryctobracon areolatus (Szépligeti), D. brasiliensis (Szépligeti), Opius bellus Gahan e Utetes anastrephae (Viereck) (Braconidae) e Aganaspis pelleranoi (Brèthes) (Figitidae), além de quatro espécimes da família Pteromalidae, tratando-se de registros inéditos de parasitóides em Viçosa e de O. bellus em Minas Gerais.

This paper presents the species diversity of fruit flies (Tephritidae), their parasitoids and hosts in the county of Viçosa, Minas Gerais State. Brazil. McPhail traps containing hydrolyzed protein were hung in three areas with several crop species, and in a natural reserve of the Atlantic Rain Forest. Ripe fruits on plants and fallen fruits were collected to obtain fruit fly and parasitoid adults. Sixteen fruit fly species were captured: Ceratitis capitata (Wiedemann), Anastrepha bezzi Lima, A. bistrigata Bezzi, A. dissimilis Stone, A. distincta Greene, A. fraterculus (Wiedemann), A. furcata Lima, A. grandis (Macquart), A. manihoti Lima, A. minensis Lima, A. montei Lima, A. obliqua (Macquart), A. pseudoparallela (Loew), A. pickeli Lima, A. serpentina (Wiedemann) and A. sororcula Zucchi. A. furcata is reported for the first time in Minas Gerais state. Furthermore, the parasitoids Doryctobracon areolatus (Szépligeti), D. brasiliensis (Szépligeti), Opius bellus Gahan, Utetes anastrephae (Viereck) (Braconidae) and Aganaspis pelleranoi (Brèthes) (Figitidae) were obtained, along with 4 specimens of Pteromalidae. This is the first report of these parasitoids in the region of Viçosa, and of O. bellus in Minas Gerais State.

Early Development and Putative Primordial Germ Cells Characterization in Dogs

Previously, three distinct populations of putative primordial germ cells (PGCs), namely gonocytes, intermediate cells and pre-spermatogonia, have been described in the human foetal testis. According to our knowledge, these PGCs have not been studied in any other species. The aim of our study was to identify similar PGC populations in canine embryos. First, we develop a protocol for canine embryo isolation. Following our protocol, 15 canine embryos at 21–25 days of pregnancy were isolated by ovaryhysterectomy surgery. Our data indicate that dramatic changes occur in canine embryo development and PGCs specification between 21 to 25 days of gestation. At that moment, only two PGC populations with distinct morphology can be identified by histological analyses. Cell population 1 presented round nuclei with prominent nucleolus and a high nuclear to cytoplasm ratio, showing gonocyte morphology. Cell population 2 was often localized at the periphery of the testicular cords and presented typical features of PGC. Both germ cell populations were positively immunostained with anti-human OCT-4 antibody. However, at day 25, all cells of population 1 reacted positively with OCT-4, whereas in population 2, fewer cells were positive for this marker. These two PGCs populations present morphological features similar to gonocytes and intermediate cells from human foetal testis. It is expected that a population of pre-spermatogonia would be observed at later stages of canine foetus development. We also showed that anti-human OCT-4 antibody can be useful to identify canine PGC in vivo.

Identification of three distinguishable phenotypes in golden retriever muscular dystrophy.

Duchenne muscular dystrophy (DMD) is a human disease characterized by progressive and irreversible skeletal muscle degeneration caused by mutations in genes coding for important muscle proteins. Unfortunately, there is no efficient treatment for this disease; it causes progressive loss of motor and muscular ability until death. The canine model (golden retriever muscular dystrophy) is similar to DMD, showing similar clinical signs. Fifteen dogs were followed from birth and closely observed for clinical signs. Dogs had their disease status confirmed by polymerase chain reaction analysis and genotyping. Clinical observations of musculoskeletal, morphological, gastrointestinal, respiratory, cardiovascular, and renal features allowed us to identify three distinguishable phenotypes in dystrophic dogs: mild (grade I), moderate (grade II) and severe (grade III). These three groups showed no difference in dystrophic alterations of muscle morphology and creatine kinase levels. This information will be useful for therapeutic trials, because DMD also shows significant, inter- and intra-familiar clinical variability. Additionally, being aware of phenotypic differences in this animal model is essential for correct interpretation and understanding of results obtained in pre-clinical trials.

Fruit flies (Diptera, Tephritidae) and their associations with native host plants in a remnant area of the highly endangered Atlantic Rain Forest in the State of Espírito Santo, Brazil.

The results presented in this paper refer to a host survey, lasting approximately three and a half years (February 2003-July 2006), undertaken in the Vale do Rio Doce Natural Reserve, a remnant area of the highly endangered Atlantic Rain Forest located in Linhares County, State of Espírito Santo, Brazil. A total of 330 fruit samples were collected from native plants, representing 248 species and 51 plant families. Myrtaceae was the most diverse family with 54 sampled species. Twenty-eight plant species, from ten families, are hosts of ten Anastrepha species and of Ceratitis capitata (Wiedemann). Among 33 associations between host plants and fruit flies, 20 constitute new records, including the records of host plants for A. fumipennis Lima and A. nascimentoi Zucchi. The findings were discussed in the light of their implications for rain forest conservation efforts and the study of evolutionary relationships between fruit flies and their hosts.