ABSTRACT
ABSTRACT Turnera sidoides (x=7) is one of the few well-studied South American autopolyploid complexes. Since polyploidy has played a prominent role within this complex, ongoing studies in T. sidoides focus on understanding the mechanisms involved in the origin and the establishment of polyploids using integrative approaches. This paper synthesises the results of more than 20 years of research on this topic. Cytogenetics analysis provided evidences for the production of unreduced male and female gametes, supporting the hypothesis of bilateral sexual polyploidization as the mechanism of origin of polyploids in T. sidoides. The finding of viable triploids suggested that unilateral sexual polyploidization could also be an important mechanism for the origin of tetraploids in T. sidoides. The occurrence of plants continuously forming many unreduced gametes would play a key role in the establishment of neopolyploids in natural populations. Also, the higher number of propagules that tetraploids contribute to subsequent generations, the ability to multiply asexually by rhizomes, and the occurrence of occasional cases of self-compatibility and successful illegitimate crosses in polyploids increase the likelihood that a low frequency of neopolyploids can be maintained in natural populations of T. sidoides. In addition, integration of cytogeographic and genetic divergence data together with past niche modelling provided further insights supporting the hypothesis that historical climatic and geomorphological events provided favourable conditions for the establishment of autopolyploids, with the wider distribution of tetraploids of T. sidoides being the result of their range expansion.
RESUMEN Turnera sidoides (x=7) es uno de los pocos complejos autopoliploides sudamericanos bien estudiados. Como la poliploidía ha tenido un papel destacado en el complejo, los estudios en curso en T. sidoides se centraron en la comprensión de los mecanismos implicados en el origen y el establecimiento de los poliploides mediante diferentes enfoques. En este trabajo se sintetizan los resultados de más de 20 años de investigación sobre este tema. El análisis citogenético proporcionó evidencias de la producción de gametos masculinos y femeninos no reducidos, sustentando la hipótesis de la poliploidización sexual bilateral como mecanismo de origen de los poliploides en T. sidoides. Sin embargo, el hallazgo de triploides fértiles sugirió que la poliploidización sexual unilateral también sería un mecanismo importante de origen de tetraploides en T. sidoides. La ocurrencia de plantas que forman continuamente gametos no reducidos desempeñaría un papel clave en el establecimiento de neopoliploides. Además, el mayor número de propágulos que los tetraploides aportan a las siguientes generaciones, la capacidad de multiplicación asexual por rizomas y los casos ocasionales de autocompatibilidad y cruzamientos ilegítimos exitosos aumentarían la probabilidad de que se mantenga una baja frecuencia de neopoliploides en las poblaciones naturales de T. sidoides. Asimismo, la integración de datos citogeográficos y de divergencia genética junto con el modelado de nicho en el pasado aportó información que sustenta la hipótesis de que los eventos climáticos y geomorfológicos históricos proporcionaron las condiciones favorables para el establecimiento y expansión de los tetraploides de T. sidoides.
ABSTRACT
Introduction: Photoperiod is, together with temperature and food availability, one of the main stimuli in the regulation of gametogenesis in a wide variety of species. Objective: To evaluate the effect of photoperiod on the production of mature gametes in cultured Arbacia dufresnii. Methods: An experiment was carried out with three varying light-dark regimes/treatments: constant light (24 h light), neutral photoperiod (12 h light, 12 h darkness), and constant darkness (24 h darkness). Twenty females were used in each treatment. All were induced to spawn and, ten randomly selected females from each treatment were induced to spawn again after 30 days. After 60 days, spawning was induced in the remaining females. The gametes were collected in filtered seawater, fixed in Davidson solution, quantified and measured per individual in triplicate in a Sedgewick-Rafter chamber. To determine maturation, fertilization success was evaluated 30 minutes after fertilization. Results: Our results showed that in the aquaculture system, after only two months, mature gametes were obtained, and in the neutral light regime there were 10 times more gametes than the number produced in wild sea urchins during the spawning period in question. We also found that with a greater exposure to light, a lower number of mature gametes was produced. Conclusions: This study suggests the viability of the production of mature gametes in a short period of time as regards Arbacia dufresnii.
Introducción: El fotoperiodo es, junto con la temperatura y la disponibilidad de alimentos, uno de los principales estímulos para el desarrollo de la gametogénesis en una amplia variedad de especies. Objetivo: Evaluar el efecto del fotoperiodo en la producción de gametas maduras de Arbacia dufresnii en un sistema de recirculación cerrado para determinar el mejor fotoperiodo para una acuicultura novedosa, enfocada en la producción de gametas con alta concentración de pigmentos para usos biotecnológicos. Métodos: Se realizó un experimento con tres regímenes/tratamientos diferentes de luz y oscuridad: luz constante (luz durante 24 h), fotoperiodo neutro (12 h de luz, 12 h de oscuridad) y oscuridad constante (oscuridad durante 24 h). Se utilizaron veinte hembras en cada tratamiento. Se indujo a todas las hembras a desovar al comienzo del experimento. Después de 30 días, diez hembras seleccionadas al azar de cada tratamiento fueron inducidas a desovar nuevamente. Al final del experimento, después de 60 días, se indujo el desove a las hembras restantes en cada tratamiento. Las gametas se recolectaron en agua de mar filtrada, se fijaron en solución de Davidson, se cuantificaron y midieron por triplicado en una cámara Sedgewick-Rafter. Para determinar la maduración, se evaluó el éxito de la fecundación después de 30 minutos de fertilización, calculando el porcentaje de huevos fertilizados. Resultados: Nuestros resultados muestran que, en el sistema acuícola, en solo dos meses se obtuvieron gametas maduras y casi 10 veces más la cantidad producida por los erizos de mar en su ambiente natural usando el fotoperiodo neutro (12 h luz:12 h oscuridad). También encontramos que la mayor exposición a la luz produce la menor cantidad de gametas maduras. Conclusión: Este estudio sugiere la viabilidad de la producción de gametos maduros en un corto período de tiempo en Arbacia dufresnii.
Subject(s)
Animals , Sea Urchins/growth & development , Arbacia/anatomy & histology , Germ Cells , Aquatic Organisms , Gonads/anatomy & histology , MexicoABSTRACT
Apomixis has been widely concerned because of its great potential in heterosis fixation. Artificial apomixis is an important direction of current apomixis research. Mitosis instead of Meiosis (MIME) produces diploid gametes that is identical with the maternal genetic composition and is a key step in the artificial creation of apomixes. This paper reviews the occurrence of MIME and its application in crop apomixis and the problems encountered, in an aim to provide reference for expanding the application of MIME in crop apomixis.
Subject(s)
Apomixis , Crops, Agricultural , Genetics , Diploidy , Germ Cells , Meiosis , MitosisABSTRACT
A large proportion of patients who survive cancer are rendered infertile as an unwanted side effect of oncotherapy. Currently accepted approaches for fertility preservation involve banking eggs/sperm/embryos or ovarian/testicular tissue before oncotherapy for future use. Such approaches are invasive, expensive, technically challenging and depend on assisted reproductive technologies (ART). Establishing a gonadal tissue bank (for cancer patients) is also fraught with ethical, legal and safety issues. Most importantly, patients who find it difficult to meet expenses towards cancer treatment will find it difficult to meet expenses towards gonadal tissue banking and ART to achieve parenthood later on. In this review an alternative strategy to regenerate non-functional gonads in cancer survivors by targeting endogenous stem cells that survive oncotherapy is discussed. A novel population of pluripotent stem cells termed very small embryonic-like stem cells (VSELs), developmentally equivalent to late migratory primordial germ cells, exists in adult gonads and survives oncotherapy due to their quiescent nature. However, the stem-cell niche gets compromised by oncotherapy. Transplanting niche cells (Sertoli or mesenchymal cells) can regenerate the non-functional gonads. This approach is safe, has resulted in the birth of fertile offspring in mice and could restore gonadal function early in life to support proper growth and later serve as a source of gametes. This newly emerging understanding on stem cells biology can obviate the need to bank gonadal tissue and fertility may also be restored in existing cancer survivors who were earlier deprived of gonadal tissue banking before oncotherapy.
ABSTRACT
O câncer não é incomum nem incurável: 85% dos doentes com menos de 45 anos diagnosticados nos EUA em 2002 sobreviveram mais de 10 anos. As maiores taxas de sobrevivência verificam‐se nos doentes jovens com câncer da mama, testicular e hematológico. Contudo, é para tratar estes tumores que são usados os fármacos mais gonadotóxicos, assim como doenças hematológicas e autoimunes também requerem terapêuticas potencialmente lesivas para as gônadas para o seu controle. O comité ético da Sociedade Americana de Medicina da Reprodução considera que existem fortes argumentos para a preservação da fertilidade em doentes jovens com cânceres tratáveis. Cabe ao médico assistente (oncologista, hematologista, cirurgião, internista) decidir o tratamento do paciente e considerar: o risco de falência ovárica/testicular; o prognóstico e o timing para iniciar tratamentos. Por outro lado, ao especialista em medicina da reprodução cabe desenvolver estratégias para preservar gâmetas/embriões de acordo com idade, tempo disponível até início do tratamento, tipo de câncer, status marital e risco de infertilidade com a terapêutica proposta. A colaboração contínua entre esses especialistas, incluindo os doentes e os parceiros, é a chave para a tomada de decisões que permitam a preservação da função reprodutiva após controle da doença de base.
Cancer is not unusual neither incurable: in USA 85% of patients under 45 years diagnosed in 2002 survived more than 10 years. The highest survival rates occur in young patients with breast, testicular and hematologic cancer. However, these tumors are treated with drugs wich most affect fertility and there is evidence that the discussion of preserving fertility is of great importance. Moreover, hematologic and autoimmune diseases may also require the use of potentially gonadotoxic drugs for their control. The ethics committee of the American Society for Reproductive Medicine believes that there are strong arguments for the preservation of fertility in young patients with treatable cancers. It is up to the physician (oncologist, hematologist, surgeon, internist) to decide the best treatment to the patient evaluating the risk of ovarian/testicular failure; the prognosis and the timing to start treatments. Moreover, the specialist in reproductive medicine should develop strategies to preserve gametes/embryos according to: age; time to treatment; type of cancer; marital status and risk of infertility, with the proposed therapy. The ongoing collaboration between these specialists, including patients and partners in the discussion, is the key to making decisions that allow the preservation of reproductive function after control of the primary disease.
Subject(s)
Humans , Male , Female , Fertility Preservation , Fertility , Neoplasms/diagnosis , Neoplasms/drug therapy , Neoplasms/therapyABSTRACT
The generation of artificial gametes is a real challenge for the scientific community today. In vitro development of human eggs and sperm will pave the way for the understanding of the complex process of human gametogenesis and will provide with human gametes for the study of infertility and the onset of some inherited disorders. However, the great promise of artificial gametes resides in their future application on reproductive treatments for all these people wishing to have genetically related children and for which gamete donation is now their unique option of parenthood. This is the case of infertile patients devoid of suitable gametes, same sex couples, singles and those fertile couples in a high risk of transmitting serious diseases to their progeny. In the search of the best method to obtain artificial gametes, many researchers have successfully obtained human germ cell-like cells from stem cells at different stages of differentiation. In the near future, this field will evolve to new methods providing not only viable but also functional and safe artificial germ cells. These artificial sperm and eggs should be able to recapitulate all the genetic and epigenetic processes needed for the correct gametogenesis, fertilization and embryogenesis leading to the birth of a healthy and fertile newborn.
Subject(s)
Child , Female , Humans , Infant, Newborn , Pregnancy , Eggs , Embryonic Development , Epigenesis, Genetic , Family Characteristics , Fertilization , Gametogenesis , Germ Cells , Infertility , Ovum , Parturition , Pluripotent Stem Cells , Spermatozoa , Stem CellsABSTRACT
Objetivo. Evaluar el efecto de dos inductores hormonales en la reproducción inducida de nicuro Pimelodus blochii. Materiales y métodos. Para los procesos experimentales fueron utilizados adultos sexualmente maduros, sometidos a tres tratamientos aplicados vía intramuscular, en dosis única de 0.25 mL/kg Ovaprim® (OVAP) (T1), 0.5 mL/kg de OVAP (T2) y 6.25 mg/kg de Extracto de Hipófisis de Carpa (EHC) (T3), para este último tratamiento la inyección fue dividida en 20 y 80%, con un intervalo de 12 h entre aplicaciones. Previo a la extracción de los gametos, los animales fueron tranquilizados por inmersión en una solución de Metanosulfonato de Tricaina (90 mg/L). El desempeño reproductivo fue evaluado mediante el índice de ovulación (hembras ovuladas/hembras tratadas), fecundidad absoluta (Fa) (ovocitos/hembra), fecundidad relativa (Fr) en función del número de ovocitos desovados por gramo de peso. La fecundación se realizó en seco y seis horas post-fecundación (HPF) se determinó la tasa de fertilidad. Resultados. La ovulación (ºh) para el T1 fue a las 297.1±30.0, T2 294.6±32.9 y T3 247.3±13.1 ºh. En todos los tratamientos se obtuvieron hembras ovuladas, donde los mayores índices de ovulación fueron obtenidos con Ovaprim® (T1 y T2) con 36.4 y 50%, respectivamente. Las tasas de fecundación obtenidas fueron mayores a un 50%, para el tratamiento 1 y 2, con valores de 74.5 y 32.7%, respectivamente. Conclusiones. El uso de inductores hormonales puede ser efectivo para garantizar la reproducción inducida del nicuro, en dosis única de 0.25 y 0.5 mL/kg de Ovaprim®.
Objective. Evaluate the effect of two hormonal inducers in induced breeding of nicuro Pimelodus blochii. Materials and methods. The experimental process used sexually mature adults exposed to three intramuscular treatments, a single dose of 0.25 mL/g Ovaprim® (OVAP) (T1), 0.5 mL/kg of OVAP (T2) and 6.25 mg/kg of pituitary carp extract (EPC) (T3), for the latter treatment the injection was divided into 20 and 80%, with an interval of 12 hours between applications. Prior to the removal of gametes, the animals were tranquilized by immersion in a Tricaine Methanesulfonate (90 mg/L) solution. Reproductive performance was evaluated using ovulation rates (females ovulated/treated females), fertility (Fa) (eggs/female), relative fertility (Fr) depending on the number of eggs spawned per gram of weight. The dry method of fertilization was used and the fertility rate was determined six hours post-fertilization (HPF). Results. The Ovulation (ºh) was: for T1 297.1±30.0, T2 294.6±32.9 and T3 247.3±13.1ºh. Ovulated females were obtained in all treatments, where the highest rates of ovulation were obtained with Ovaprim ® (T1 and T2) with 36.4 and 50% respectively. Fertilization rates were higher than 50% for treatments 1 and 2, with values of 74.5 and 32.7% respectively. Conclusions. The use of hormonal inducers may be effective to ensure nicuro induced reproduction with a single dose of 0.25 and 0.5 mL/kg Ovaprim®.
Subject(s)
Animals , Germ Cells , ReproductionABSTRACT
Se caracterizó el ciclo reproductivo de Mytilopsis leucophaeata (Conrad, 1831) en organismos colectados mensualmente durante un ciclo anual en la laguna de Tampamachoco, Túxpam, Veracruz, que se ubica en la costa del Golfo de México en la Región Terrestre Prioritaria (RTP-103) de CONABIO considerada sitio RAMSAR 1602 en México. Los resultados histológicos indican que M. leucophaeata presenta cuatro etapas gametogénicas: gametogénesis, madurez, desove total para hembras y expulsión parcial para machos. Uno de los principales factores que influyen en el desove sincrónico de gametos tanto en machos como en hembras es la salinidad, en los meses de enero a marzo.
The reproductive cycle of Mytilopsis leucophaeata (Conrad, 1831) was characterized in organisms collected monthly during an annual cycle in Tampamachoco lagoon Tuxpam-Veracruz, located on the coast of the Gulf of Mexico in the Terrestre Prioritaria Region (RTP-103) of CONABIO considered a RAMSAR 1602 site in Mexico. Histological results indicated that M. leucophaeata has four gametogenic stages: gamete, maturity, female's total spawning and partial expulsion inmales. One of the main factors that influence the synchronous spawning gametes in both males and females is salinity, in the months of January to March.
Subject(s)
Animals , Reproduction/physiology , Bivalvia/physiology , Gametogenesis , MexicoABSTRACT
The Alchornea triplinervia specie belongs to the Euphorbiaceae family, one of the main families of the Brazilian flora. In order to contribute to a better understanding of the specie, a counting of chromosome number and the microsporogenesis analysis of A. triplinervia were done. The inflorescences were collected in the municipalities of Paranavaí and Diamante do Norte, State of Paraná, Brazil, and the slides were prepared by squashing technique and staining with 1% acetic carmine. The analysis were performed using an optical microscope and showed a chromosome number for the specie equal to 2n=8x=72. Irregularities in the chromosome segregation process were the main meiotic abnormalities, presenting typical polyploid behavior. Other irregularities were observed; however, at low frequency without compromising the pollen grain formation of the analyzed plants.
A espécie Alchornea triplinervia pertence à família Euphorbiaceae, uma das principais famílias da flora brasileira. Visando a contribuir para um melhor entendimento da espécie, foi realizada a contagem do número de cromossomos e a análise da microsporogênese de A. triplinervia. As Inflorescências foram coletadas nos Municípios de Paranavaí e Diamante do Norte, no Estado do Paraná, Brasil, sendo as lâminas preparadas pela técnica de esmagamento e coradas com carmim acético 1%. As análises foram realizadas ao microscópio óptico, revelando um número cromossômico para a espécie igual a 2n=8x=72. Irregularidades no processo de segregação dos cromossomos foram as principais anormalidades meióticas, mostrando comportamento típico de poliploides. Outras irregularidades foram observadas, porém, em baixa frequência, não comprometendo a formação dos grãos de pólen das plantas analisadas.
ABSTRACT
Almost 90 percent of species of the genus Passiflora are native to the American continent, with high commercial value due to the fact that some species are used for human food while others have ornamental and medical qualities. Passiflora serrato-digitata is one of the species that integrates the Paraná Agronomic Institute germoplasm bank at its experimental base in Londrina, PR, Brazil. Collected flower buds were fixed in ethanol/acetic acid (3:1 v/v) for 24h, transferred to 70 percent alcohol and stored under refrigeration. Slides were prepared by the squashing technique and stained with 1.0 percent propionic carmine; they were analyzed under an optic microscope. Irregularities in the chromosome segregation process of P. serrato-digitata have been verified by meiotic behavior analysis. These comprised precocious migration to poles in metaphase I and II, non-oriented chromosomes in metaphase plate in metaphase I and II, laggard chromosomes in anaphase I and II towards the formation of micronucleus in telophase I and II, and microspores in tetrads. Chromosome stickiness was another irregularity reported in the Passiflora genus for the first time. These irregularities which also contributed to the formation of monads, dyads and triads, resulted in normal imbalanced 2n and 4n microspores. According to the observed Meiotic Index of 71.83 percent, this species is not meiotically stable.
Cerca de 90 por cento das espécies do gênero Passiflora são nativas das Américas, sendo que aproximadamente 200 espécies são nativas do Brasil. Possuem grande importância comercial, pois algumas espécies são utilizadas na alimentação humana, outras apresentam propriedades medicinais e ornamentais. A espécie Passiflora serrato-digitata faz parte do banco de germoplasma do Instituto Agronômico do Paraná - IAPAR, estação experimental de Londrina, PR. Botões florais colhidos foram fixados em etanol/ácido acético (3:1 v/v) por 24 horas, transferidos para álcool a 70 por cento e acondicionado sob refrigeração. As lâminas foram preparadas pela técnica de esmagamento e coradas com carmim propiônico a 1,0 por cento e observadas ao microscópio óptico. Por meio da análise do comportamento meiótico, foram verificadas irregularidades no processo de segregação dos cromossomos de P. serrato-digitata, tais como migração precoce para os pólos em metáfase I e II, cromossomos não orientados na placa equatorial em metáfase I e II, cromossomos retardatários em anáfase I e II, levando a formação de micronúcleo em telófases I e II e micrósporos em tétrades. Outra irregularidade observada foi aderência cromossômica, relatada pela primeira vez no gênero Passiflora, que também pode ter contribuído para a formação de mônades, díades, tríades, as quais foram observadas, resultando em micrósporos normais, desbalanceados, 2n e 4n. De acordo com o Índice Meiótico de 71,83 por cento observado, essa espécie pode ser classificada como não estável meioticamente.
ABSTRACT
Através desse trabalho, objetiva-se abordar o tema de doação de gametas e do anonimato envolvendo este ato na reprodução medicamente assistida. Analisando rapidamente o caráter técnico da doação e seleção dos gametas e a necessidade de uma legislação específica sobre o assunto nos diferentes países do mundo que adotaram esse método, diante da pluralidade social existente. Consideram-se os aspectos éticos e legais vigentes no Brasil ditados pela Resolução do Conselho Federal de Medicina nº 1.358/93 que determina as condutas dos médicos brasileiros e define, dentre outros aspectos, o da doação e do anonimato, envolvendo o aspecto autonomia. A necessidade de proteção dos sujeitos através do termo de consentimento informado ou de recusa informada, permitindo garantir a informação e esclarecimento necessário ao casal que decide submeter-se aos planos de reprodução medicamente assistida assim como ao doador que, por sua vez, também deve dar garantias escritas quanto à espontaneidade e à alienação dos direitos sobre os gametas à instituição que se torna a responsável por estes. Tudo isso, aliado à veracidade e confidencialidade, compõe os elementos fundamentais para a manutenção do anonimato entre o doador e o receptor. Anonimato este, ainda muito discutido pelos estudiosos de diversas áreas e países.
This article aims to address the issue of the donation of gametes and the anonymity involved in this act of medically-assisted reproduction. It briefly discusses the technical aspects of the donation and selection of gametes and the need for specific legislation on the issue in various countries that have adopted this method, in view of the plurality of different social systems in the world today. The article addresses the legal and ethical issues that are currently being aired in Brazil, and the rulings contained in the Federal Medical Council Resolution 1,358/93, which rules on the conduct of physicians in Brazil and defines, among other things, an act of donation and anonymity, in a way that addresses the question of autonomy. The need for the protection of subjects by way of terms of informed consent or informed refusal, ensuring that necessary information and clarification is made available both to the couple that decide to submit themselves to medically-assisted reproduction and to the donor, who should, in turn, give written assurance of his or her free consent and willingness to cede any rights regarding the gametes to the institution that has taken responsibility for them. All of this, in combination with veracity and confidentiality, are essential if anonymity between donor and recipient is to be upheld. This question of anonymity has been much discussed by scholars from various fields and various parts of the world.
Subject(s)
Humans , Directed Tissue Donation , Germ Cells , Insemination, Artificial, Heterologous/ethics , Insemination, Artificial, Heterologous/legislation & jurisprudence , ReproductionABSTRACT
Papillomaviruses are described selectively infecting epithelial tissues and are associated with many forms of cancer in different species. Considering the widespread dissemination of papillomatosis in livestock, interest is being centred on possible forms of viral transmission and respective mechanisms. In the present study, we report the detection of bovine papillomavirus (BPV) DNA sequences in female reproductive tract tissues, fluids and oocytes from slaughtered bovines not afflicted by cutaneous papillomatosis. BPV-2 DNA sequences were found in ovarian and uterine tissues as well as in oocytes, cumulus cells and uterine flushings. The presence of papillomavirus sequences in reproductive organ tissues and fluids shows that viral infection in organisms can be verified in others tissues, not only in epithelial ones. The present findings alert to the possibility of BPV transmission in embryo transfer programs and assisted fertilization procedures.
Os vírus do papiloma bovino, descritos como agentes infectantes específicos do epitélio, têm sido associados a diversas formas de câncer em diferentes espécies animais. Dada a intensa disseminação da papilomatose nos rebanhos, a investigação de diferentes formas de transmissão e seus respectivos mecanismos tem exigido especial atenção. No presente estudo, é relatada a detecção de seqüências genômicas do papilomavirus bovino (BPV) em ovócitos e tecidos do trato reprodutivo oriundos de fêmeas abatidas comercialmente, não apresentando papilomatose cutânea. A presença de DNA de BPV-2 em tecidos do trato reprodutivo, lavado uterino, ovócitos e células do cumulus traz evidências de que a infecção viral pode se desenvolver fora do tecido epitelial. Esses achados alertam para a possibilidade de transmissão do BPV através dos procedimentos de transferência de embriões e de fertilização in vitro.
ABSTRACT
Papillomaviruses are described selectively infecting epithelial tissues and are associated with many forms of cancer in different species. Considering the widespread dissemination of papillomatosis in livestock, interest is being centred on possible forms of viral transmission and respective mechanisms. In the present study, we report the detection of bovine papillomavirus (BPV) DNA sequences in female reproductive tract tissues, fluids and oocytes from slaughtered bovines not afflicted by cutaneous papillomatosis. BPV-2 DNA sequences were found in ovarian and uterine tissues as well as in oocytes, cumulus cells and uterine flushings. The presence of papillomavirus sequences in reproductive organ tissues and fluids shows that viral infection in organisms can be verified in others tissues, not only in epithelial ones. The present findings alert to the possibility of BPV transmission in embryo transfer programs and assisted fertilization procedures.
Os vírus do papiloma bovino, descritos como agentes infectantes específicos do epitélio, têm sido associados a diversas formas de câncer em diferentes espécies animais. Dada a intensa disseminação da papilomatose nos rebanhos, a investigação de diferentes formas de transmissão e seus respectivos mecanismos tem exigido especial atenção. No presente estudo, é relatada a detecção de seqüências genômicas do papilomavirus bovino (BPV) em ovócitos e tecidos do trato reprodutivo oriundos de fêmeas abatidas comercialmente, não apresentando papilomatose cutânea. A presença de DNA de BPV-2 em tecidos do trato reprodutivo, lavado uterino, ovócitos e células do cumulus traz evidências de que a infecção viral pode se desenvolver fora do tecido epitelial. Esses achados alertam para a possibilidade de transmissão do BPV através dos procedimentos de transferência de embriões e de fertilização in vitro.