Biomedical subjects

Daniele Zambelli

Publications and source records attributed to Daniele Zambelli.

6 recordsLinked to original sources

PubMed2006

In vitro production of cat blastocysts of predetermined sex using flow cytometrically sorted semen.

Sex preselection in cats can have applications for both breeding purposes and as an experimental model for endangered felids. The present study examined the ability to produce cat embryos from in vitro fertilization (IVF) of in vitro matured (IVM) cat oocytes with flow cytometrically sorted spermatozoa and to verify the sex of the embryos obtained from sexed spermatozoa by PCR. In the first experiment, a total of 224 oocytes were fertilized with spermatozoa from six ejaculates sorted without sex separation. The sorting process did not influence the cleavage rate (sorted 44.0% versus unsorted 46.1%), day 6 morula-blastocyst rate (sorted 26.6% versus unsorted 29.6%) and day 7 blastocyst rate (sorted 16.5% versus unsorted 16.5%). In the second experiment, a total of 84 IVM oocytes were fertilized with sorted X- and Y-chromosome bearing spermatozoa from four ejaculates in order to obtain embryos of preselected sex. Embryonic sex determination by PCR revealed that 21 out of 24 embryos reaching morula/blastocyst stage (87.5%) were of the desired sex. In particular 12 out of 14 embryos (85.7%) derived from X-bearing spermatozoa were female and 9 embryos out of 10 (90%) derived from Y-bearing spermatozoa were male. Our results show, for the first time, that X- and Y-chromosome bearing spermatozoa sorted by high-speed flow cytometry can be successfully used in an IVM-IVF system to obtain cat embryos of a predetermined sex.

Animals↗

PubMed2006

Semen collection in cats: techniques and analysis.

Sperm collection permits to obtain material for artificial insemination, diagnostic purposes, and use in research. Collections via artificial vagina (AV) and electroejaculation (EE) are the most commonly used in the cat and permit to obtain ejaculates with good quality, but EE seems to be the method of choice. Other methods of semen collection, such as epididymal squeezing or slicing, to achieve material for research have been reported. Semen analysis is essential for the fertility evaluation of male felids, but some of the diagnostic procedures used in other species are difficult or impossible to duplicate, due to the small volume of the cat ejaculate. In practice, sperm motility and viability (using eosin-nigrosin staining), morphology and sperm concentration should be evaluated, even if determination of sperm membrane and acrosomal integrity (using transmission electromicroscopy or fluorescence microscopy), semen chemistries and other parameters can be important for testing both fresh and frozen-thawed sperm. This manuscript reviews the techniques for semen collection and analysis.

Acrosome Reaction↗

PubMed2005

Vaginal and cervical modifications during the estrus cycle in the domestic cat.

A thorough knowledge of the genital tract anatomy and vaginal and cervical modifications during the phases of estrus cycle of the female cat is necessary to enhance success of assisted feline reproductive technologies or for other diagnostic or therapeutic purposes. There are few studies of the gross anatomy of the genital tract in the queen. The vestibule is large in comparison to the vagina; the latter has a narrow lumen, which is further constricted by the prominent dorsal median fold. The cervix is oriented obliquely between the uterine body and vagina. Vaginal and cervical changes in association with the estrous cycle have been reported in some species and two recent studies investigated this aspect in the cat. This paper reviews the relevant literature, with particular emphasis on recent studies.

Anestrus↗

PubMed2005

Transcervical artificial insemination in the cat.

Many studies have reported new reproductive techniques for reproduction in endangered non-domestic felids. Artificial insemination is an important tool for developing breeding programs. This manuscript reviews recent progress in feline artificial insemination, with particular emphasis on intrauterine sperm deposition. Intrauterine insemination of felids results in higher fertilization rates than intravaginal insemination, despite insemination with fewer sperm. Although surgical insemination was utilized historically, there are some reports of catheterization of the cervix of the queen. Recently, a new technique and catheter were proposed for transcervical insemination of fresh or frozen-thawed semen.

Animals↗

PubMed2004

Effect of EGF on in vitro maturation of domestic cat oocytes.

The objective of this study was to evaluate the influence of different concentrations of epidermal growth factor (EGF) on in vitro maturation of domestic cat oocytes. A total of 444 cat oocytes were matured in MSOF (maturation synthetic oviductal fluid) in the presence of varying EGF concentrations: (1) MSOF (control); (2) MSOF+10 ng/mL EGF (EGF10); (3) MSOF+25 ng/mL EGF (EGF25); and (4) MSOF+50 ng/mL EGF (EGF50). After IVM, oocytes were in vitro fertilized to verify the effect of adding EGF on cytoplasmic maturation. Cleavage rate was recorded and noncleaving oocytes were stained with Hoechst 33258 and examined to determine nuclear maturation rate. Cleaved zygotes were cultured in vitro and embryo stages were evaluated on days 6 and 7. There was no difference among groups in the total number of oocytes reaching the metaphase II (MII) stage (P>0.05). The EGF25 group had the highest (P<0.01) blastocyst yield (37.5%) and developmental competence (60.9%). Cleavage rate and resulting morulae and blastocysts on day 6 for EGF25 group were higher (P<0.01) than control and EGF50 groups. Although EGF did not significantly enhance nuclear maturation rate, it had a dose-related positive effect on cytoplasmic maturation, since the oocyte's ability to cleave and reach the blastocyst stage was improved at 25 ng/mL, with intermediate improvement at 10 ng/mL, but 50 ng/mL had no significant benefit. In conclusion, the addition of EGF to the maturation medium enhanced cytoplasmic maturation of cat oocytes in vitro.

Animals↗

PubMed2004

Correlation between fetal age and ultrasonographic measurements during the second half of pregnancy in domestic cats (Felis catus).

We ultrasonographically evaluated the prenatal development in cats, from Day 30 to the end of pregnancy, subjecting a group of pregnant cats (n = 8) to daily ultrasonographic examinations. The ultrasonographic images allowed us to measure the diameter of the fetal abdomen, the biparietal diameter of the fetal skull and the diameter of the fetal stomach. A correlation between these measurements and gestational age was found with a linear, parabolic and exponential regression analysis. From Days 38 to 43 after breeding we also performed fetal gender determination by evaluating the external genitalia. All queens successfully carried their pregnancies to term. This study compiled useful new data in order to clinically monitor the normal course of pregnancy in cats and to determine gestational age.

Abdomen↗