Adição de plasma seminal ao sêmen descongelado e taxa de prenhez de ovelhas inseminadas em tempo fixo / Addition of seminal plasma to frozen-thawed semen and pregnancy rate of fixed time inseminated ewes

Avaliou-se o efeito da adição de plasma seminal ovino ao sêmen descongelado sobre a taxa de prenhez de ovelhas em rebanho comercial. Cento e setenta e quatro ovelhas cruza Texel foram distribuídas em quatro tratamentos: T1) inseminação artificial cervical (IAC) com sêmen descongelado (SD) diluído em solução tampão fosfato salino (PBS); T2) IAC com SD e adição de plasma seminal ovino; T3) grupo-controle I: IAC com sêmen fresco diluído em PBS; T4) grupo-controle II: inseminação artificial por laparoscopia com SD diluído em PBS. Para indução de cio, utilizaram-se esponjas impregnadas com acetato de medroxiprogesterona (MAP) por 12 dias, com aplicação intramuscular de 400 UI de eCG (Novormon®) e de 37,5µg de cloprostenol sódico (Sincrocio®), no dia da retirada das esponjas. O aparecimento de cio foi monitorado com rufiões vasectomizados a partir da retirada das esponjas até a inseminação artificial em tempo fixo - 54 a 60 horas. A taxa de prenhez do tratamento com adição de plasma seminal ao sêmen descongelado (7,0%) não diferiu (P>0,05) do tratamento sem adição de plasma (4,3%), entretanto foi menor (P<0,05) se comparada à taxa de prenhez dos grupos-controle I inseminação via cervical superficial com sêmen fresco diluído (50,0%) e II inseminação via laparoscopia com sêmen descongelado (39,4%). A inseminação artificial por via cervical superficial com adição de plasma seminal ao sêmen descongelado não elevou o percentual de prenhez em valores que justifiquem a indicação desta biotecnologia em rebanhos comerciais de ovinos.

The effect of seminal plasma addition to thawed-frozen ram semen on the pregnancy rate of commercial herd ewes was evaluated. One hundred and seventy-four crossbred Texel sheep were allocated to four treatments: T1) cervical artificial insemination (CAI) using frozen-thawed semen (FTS) diluted in phosphate buffered saline solution (PBS); T2) CAI using FTS diluted in ovine seminal plasma; T3) control group I: CAI using fresh semen diluted in PBS; T4) control group II: laparoscopic insemination using FTS diluted in PBS. Estrus induction was performed with medroxiprogesterone acetate (MAP) impregnated sponges for 12 days, followed by intramuscular injection of 400 IU of eCG (Novormon®) and 37.5µg of sodium cloprostenol (Sincrocio®) on the day of sponge removal. Estrus was monitorated with vasectomized rams, beginning at the time of the sponge removal until the fixed time artificial insemination - 54 to 60 hours. The pregnancy rate of FTS diluted in seminal plasma treatment (7.0%) did not differ (P>0.05) for the treatment without addition of seminal plasma (4.3%), however it was lower (P<0.05) when compared to the pregnancy rate of the cervical inseminated control I group with PBS diluted fresh semen (50.0%) and laparoscopic inseminated control group II with PBS diluted FTS (39.4%). The cervical artificial insemination with the addition of seminal plasma to frozen-thawed semen did not increase the pregnancy rate at acceptable values to make this biotechnology useful on commercial herds.

Mining microorganism EST databases in the quest for new proteins

Microorganisms with large genomes are commonly the subjects of single-round partial sequencing of cDNA, generating expressed sequence tags (ESTs). Usually there is a great distance between gene discovery by EST projects and submission of amino acid sequences to public databases. We analyzed the relationship between available ESTs and protein sequences and used the sequences available in the secondary database, clusters of orthologous groups (COG), to investigate ESTs from eight microorganisms of medical and/or economic relevance, selecting for candidate ESTs that may be further pursued for protein characterization. The organisms chosen were Paracoccidioides brasiliensis, Dictyostelium discoideum, Fusarium graminearum, Plasmodium yoelii, Magnaporthe grisea, Emericella nidulans, Chlamydomonas reinhardtii and Eimeria tenella, which have more than 10,000 ESTs available in dbEST. A total of 77,114 protein sequences from COG were used, corresponding to 3,201 distinct genes. At least 212 of these were capable of identifying candidate ESTs for further studies (E. tenella). This number was extended to over 700 candidate ESTs (C. reinhardtii, F. graminearum). Remarkably, even the organism that presents the highest number of ESTs corresponding to known proteins, P. yoelii, showed a considerable number of candidate ESTs for protein characterization (477). For some organisms, such as P. brasiliensis, M. grisea and F. graminearum, bioinformatics has allowed for automatic annotation of up to about 20 of the ESTs that did not correspond to proteins already characterized in the organism. In conclusion, 4093 ESTs from these eight organisms that are homologous to COG genes were selected as candidates for protein characterization