Determinação da dose inseminante e embriogênese na fertilização artificial de tambaqui (Colossoma macropomum) / Determination of insemination dose and embryonic development in the artificial fertilization of tambaqui (Colossoma macropomum)

Determinou-se a dose inseminante para fertilização artificial e descreveu-se o desenvolvimento embrionário de tambaqui (Colossoma macropomum). Os gametas foram coletados de reprodutores induzidos hormonalmente. Foi realizada fertilização artificial nas proporções de espermatozoides/ovócito de D1-50.666; D2-75.999; D3-101.332; D4-126.665; D5-151.998. O desenvolvimento embrionário foi acompanhado por meio de observações periódicas em estereoscópio até a eclosão dos ovos. Na fase de fechamento do blastóporo foi calculada a taxa de fertilização nas diferentes doses inseminantes. A porcentagem de fertilização aumentou de forma linear segundo a equação Ŷ =0,050 + 0,00000773X (R²=97,5), atingindo um platô em 84% na proporção de 102.486 espermatozoides/ovócito. Os embriões apresentaram segmentação meroblástica discoidal, típica de ovos telolécitos, com eclosão ocorrendo aos 357 horas-grau após a fertilização. Conclui-se que o desenvolvimento embrionário de tambaqui obedece ao esperado para peixes com ovos telolécitos e recomenda-se o uso da dose inseminante de aproximadamente 100.000 espermatozoides/ovócito na rotina de fertilização artificial dessa espécie.

The objective of this research was to determine the insemination dose for artificial fertilization and describe the embryonic development of tambaqui (Colossoma macropomun). The gametes were collected from induced breeding hormonally. An artificial fertilization was performed with different sperm/oocyte ratios of D1-50666, D2-75999, D3-101 332, 126 665-D4, D5-151 998 sperm/oocyte. Embryonic development was monitored through periodic stereoscopic observations until hatching. When embryos reached the blastopore closure stage, the rate of fertilization in different insemination doses was calculated. A regression equation was estimated to determine the ideal proportion of the gametes. The fertilization rate increased linearly according to the equation Ŷ = 0.050 + 0.00000773 X (R² = 97.5), up to the proportion of 102.486 spermatozoa/oocyte, and, from this point, the fertilization rate was maintained at 84%. The embryonic development of tambaqui was meroblastic discoidal, as expected from telolecithal eggs and we recommend the use of the insemination dose of approximately 100.000 sperm/oocyte in the artificial fertilization of tambaqui.

Male accessory gland substances from Aedes albopictus affect the locomotor activity of Aedes aegypti females

Dengue is one of the world’s most important mosquito-borne diseases and is usually transmitted by one of two vector species: Aedes aegypti or Aedes albopictus . These two diurnal mosquitoes are frequently found coexisting in similar habitats, enabling interactions between adults, such as cross-mating. The objective of this study was to assess cross-mating between Ae. aegypti females and Ae. albopictus males under artificial conditions and evaluate the locomotor activity of Ae. aegypti virgin females injected with male accessory gland (MAG) homogenates to infer the physiological and behavioural responses to interspecific mating. After seven days of exposure, 3.3-16% of Ae. aegypti females mated with Ae. albopictus males. Virgin Ae. aegypti females injected with conspecific and heterospecific MAGs showed a general decrease in locomotor activity compared to controls and were refractory to mating with conspecific males. The reduction in diurnal locomotor activity induced by injections of conspecific or heterospecific MAGs is consistent with regulation of female reproductive activities by male substances, which are capable of sterilising female Ae. aegypti through satyrisation by Ae. albopictus .

Morphological and morphometrical assessment of spermathecae of Aedes aegypti females

The vectorial capacity of Aedes aegypti is directly influenced by its high reproductive output. Nevertheless, females are restricted to a single mating event, sufficient to acquire enough sperm to fertilize a lifetime supply of eggs. How Ae. aegypti is able to maintain viable spermatozoa remains a mystery. Male spermatozoa are stored within either of two spermathecae that in Ae. aegypti consist of one large and two smaller organs each. In addition, each organ is divided into reservoir, duct and glandular portions. Many aspects of the morphology of the spermatheca in virgin and inseminated Ae. aegypti were investigated here using a combination of light, confocal, electron and scanning microscopes, as well as histochemistry. The abundance of mitochondria and microvilli in spermathecal gland cells is suggestive of a secretory role and results obtained from periodic acid Schiff assays of cell apexes and lumens indicate that gland cells produce and secrete neutral polysaccharides probably related to maintenance of spermatozoa. These new data contribute to our understanding of gamete maintenance in the spermathecae of Ae. aegypti and to an improved general understanding of mosquito reproductive biology.

Comparison of intrauterine insemination and in vitro fertillization for the treatment of unexplained infertility

This retrospective study was performed to compare the pregnancy rates [PR] in patients treated with either in vitro fertilization [IVF] or controlled ovarian superstimulation [COS] and intrauterine insemination [IUI] in patients with unexplained infertility. In Group A, 77 females underwent 125 treatment cycles of IVF; in Group B, 54 females underwent 131 treatment cycles of COS and IUI. Pregnancy rates per cycle initiated in Group A and Group B were 17.6% and 19%, [P>0.05]. We concluded that COS and IUI are as effective as IVF in patients with unexplained infertility

Comparison of controlled ovarian superstimulation with or without intrauterine insemination for the treatment of unexplaned infertility

This retrospective study was performed to compare the pregnancy rates [PR] in patients treated with either controlled ovarian superstimulation [COS] and intrauterine insemination [IUI] or COS and timed intercourse [TI] in patients with unexplained infertility. Fifty-seven females underwent 98 treatment cycles of COS and IUI and 30 females underwent 96 treatment cycles of COS and TI. Pregnancy rates [PR] per cycle in the groups treated with COS and either IUI or TI were 18.4% and 3.1% respectively [P<0.05]. We concluded that COS and IUI are an effective treatment compared with COS and TI in patients with unexplained infertility

Niveles de progesterona plasmática durante los primeros siete días postinseminación en vaquillas Holstein repetidoras y de primer servicio / Progesterone concentration in plasma from repeat-breeding and first-service Holstein heifers during the first 7 days postinsemination

Se evaluó la función lútea durante los primeros siete días siguientes al servicio en vaquillas Holstein repetidoras y de primer servicio. Con este objeto se formaron dos grupos; el primero con 12 vaquillas de primera servicio y el segundo con 18 vaquillas repetidoras. Todos los animales fueron sangrados diariamente desde el día de la inseminación hasta el día 7 posinseminación. La sangre heperinizada se centrifugó inmediatamente después de su obtención para separar el plasma, el cual se procesó por radioinmunoanálisis para determinar los niveles de progesterona. Las concentraciones de progesterona plasmática no difirieron (P> 0.05) entre vaquillas repetidoras y de primer servicio en ninguno de los días evaluados. Asimismo, se compararon las concentraciones de progesterona entre vaquillas que quedaron gestantes y aquellas que no concibieron, sin encontrar diferencias (P> 0.05). En este estudio nada evidenció que la deficiencia en la función del cuerpo lúteo durante los primeros siete días postservicio, sea una causa significativa de infertilidad en vaquillas Holstein.

Intra-uterine insemination with superovulation in the treatment of male infertility

The value of intra-uterine insemination [IUI] coupled with Superovulation was studied in two groups of couples infertile because of male subfertility. IUI was carried out on 38 women during 78 treatment cycles after stimulation of ovulation with Clomid and human menopausal gonadotrophin [HMG] and on 29 women during 79 treatment cycles without stimulation. The pregnancy rate per patient [28.9%] and per treatment cycle [14.1%] was significantly higher in the stimulated group [p = 0.05 and p = 0.01, respectively]. This could be attributed to a significantly higher number of follicles recruited [p < 0.001], since there was homogeneity between the two groups for other confounding factors. It is concluded that Superovulation improves the pregnancy rate in couples with male subfertility treated with IUI