Publications by authors named "Amanda F Zangirolamo"

The use of C-type natriuretic peptide (CNP) in the interaction with the oocyte and in the temporary postponement of spontaneous meiosis resumption has already been well described. However, its action in pre-implantation developmental-stage embryos is yet to be understood. Thus, our study aimed to detect the presence of the canonical CNP receptor (natriuretic peptide receptor, NPR2) in germinal vesicle (GV)-, metaphase II (MII)-, presumptive zygote (PZ)-, morula (MO)-, and blastocyst (BL)-stage embryos and, later, to observe possible modulations on the embryos when co-cultured with CNP.

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  • The study investigated the impact of prostaglandin F2α (PGF2α) combined with gonadotropin-releasing hormone (GnRH) on ovulation in young Nellore heifers undergoing a fixed-time superovulation (SOV) program.
  • A total of 35 heifers were treated with a complex hormonal protocol, followed by artificial insemination, to assess embryo quantity and viability.
  • Results showed no significant difference in the number of total or viable embryos between the control and treatment groups, suggesting PGF treatment did not enhance embryo production in these heifers.
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  • Pregnancy losses in cattle negatively impact the economy and the overall production chain.
  • Early embryonic failure is a significant issue in the embryo industry, making it hard to identify embryo death during early gestation.
  • The review discusses reproductive failures, the effect of various reproductive biotechniques on early embryonic loss, and strategies to reduce these losses, including embryo evaluation, proper recipient selection, and considering paternal effects.
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The microbiota plays an important role in numerous physiological processes, pathogenesis, development, and metabolism in different animal species. In humans, several studies have demonstrated an association between the vaginal microbiota and fertility rates, and even success in assisted reproduction techniques. In the context of cattle reproduction, although few studies have addressed the microbiota in a healthy state (which is not associated with diseases that affect the reproductive tract of cows), changes in its composition also seem to influence fertility.

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  • The study focuses on understanding the vaginal microbiota of cows and its importance in reproduction and fertility, using long-read sequencing (PacBio) to characterize it at the species level.
  • Researchers compared results from PacBio with those obtained from short-read sequencing (Illumina), noting that while Illumina captured more species, PacBio identified more unique, rare species.
  • The findings reveal that the sequencing method can significantly affect the analysis of vaginal microbiota, suggesting a need for improved databanks and methodologies in future research.
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In the present study, there was an evaluation of in vitro embryo production (IVEP) in Bos indicus donor cows with small or large antral follicle counts (AFCs) when there was synchronization of follicular dynamics among cows before ovum pick-up (OPU). Donor cows classified as having small or large AFC were submitted to OPU/IVEP program (Experiment-I) or had follicular-stage synchronization imposed before OPU/IVEP (Experiment-II). In Experiment-I, the cows with a large AFC had a greater (P < 0.

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The number of embryos produced by fertilization (IVF) has grown exponentially in recent years. Recently, for the first time, the number of embryos produced and transferred was significantly higher than the number developed worldwide. In this context, a particular boost occurred with ovum pick-up (OPU) and embryos produced in North America, and this technology is becoming more prominent for commercial dairy farms.

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Mitochondrial function, largely regulated by the dynamics of this organelle, is inextricably linked to the oocyte health. In comparison with most somatic cells, mitochondria in oocytes are smaller and rounder in appearance, suggesting limited fusion. The functional implications of this distinct morphology, and how changes in the mitochondrial shape translate to mitochondrial function in oogenesis is little understood.

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Among the reproductive biotechnologies, in vitro embryo production (IVEP) is an important tool for multiplying genetic material of superior merit. Recently, the number of embryos produced and transferred in vitro became significantly higher than that produced in vivo worldwide. In this context, the enhancement was attributable to ovum pick-up (OPU).

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Over the years, the dairy cow has been selected and managed for high performance and efficiency in milk production. Thus, different factors influence the fertility of dairy cows of high productivity. It has been observed that genetic selection for large productions and metabolic adaptations may explain the greater requirement to maintain reproduction at satisfactory levels.

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Reproductive biotechniques such as embryo production are important tools to increase the reproductive performance in cattle in a short time. In this context, the antral follicle count (AFC), which reflects the population of antral follicles present in an ovary, has been indicated as an important phenotypic characteristic related to female fertility and closely correlated to the performance of and embryo production (IVEP). A positive correlation was evidenced between AFC and oocyte retrieval by ovum pick up (OPU) sessions and and with the number of embryos produced.

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Oocyte mitochondria are increased in number, smaller, and rounder in appearance than mitochondria in somatic cells. Moreover, mitochondrial numbers and activity are narrowly tied with oocyte quality because of the key role of mitochondria to oocyte maturation. During oocyte maturation, mitochondria display great mobility and cluster at specific sites to meet the high energy demand.

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Ticks are able to transmit tick-borne infectious agents to vertebrate hosts which cause major constraints to public and livestock health. The costs associated with mortality, relapse, treatments, and decreased production yields are economically significant. Ticks adapted to a hematophagous existence after the vertebrate hemostatic system evolved into a multi-layered defense system against foreign invasion (pathogens and ectoparasites), blood loss, and immune responses.

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Background: Ticks cause massive damage to livestock and vaccines are one sustainable substitute for the acaricides currently heavily used to control infestations. To guide antigen discovery for a vaccine that targets the gamut of parasitic strategies mediated by tick saliva and enables immunological memory, we exploited a transcriptome constructed from salivary glands from all stages of Rhipicephalus microplus ticks feeding on genetically tick-resistant and susceptible bovines.

Results: Different levels of host anti-tick immunity affected gene expression in tick salivary glands; we thus selected four proteins encoded by genes weakly expressed in ticks attempting to feed on resistant hosts or otherwise abundantly expressed in ticks fed on susceptible hosts; these sialoproteins mediate four functions of parasitism deployed by male ticks and that do not induce antibodies in naturally infected, susceptible bovines.

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Bovine hemoplasmas are bacteria found on the erythrocyte surface or free in the plasma of cattle. The aim of the present study was to evaluate the occurrence of 'Candidatus Mycoplasma haemobos' ('C. M.

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