Reproductive Technologies Used in Female Neo-Tropical Hystricomorphic Rodents.

Kavita Ranjeeta Lall,Gary Wayne Garcia,Kegan Romelle Jones

doi:10.3390/ani12050618

Abstract

Simple SummaryThis literature review focused on the reproductive technologies used in female neo-tropical hystricomorphic rodents. Reproductive technologies aid in efficient reproduction, which is important in these species as they are hunted and valued for their meat. Knowledge of the anatomy and physiology would aid in assisted reproductive techniques, thus attention was given to these areas. Within this group of rodent species there were similar characteristics, some of which have been highlighted as well as any unique features. Some reproductive technologies used included colpocytology, ultrasonography, and hormonal analysis.This is the second of two literature reviews that focuses on the female reproductive anatomy and reproductive technologies used in selected neo-tropical hystricomorphic rodents. The rodents chosen included the agouti (Dasyprocta leporina), the capybara (Hydrochoerus hydrochaeris), and the paca (Cuniculus paca). Over seventy references were used, spanning the years 1919–2021. Knowledge of the reproductive tract is important in understanding any unique features, which may affect the use of reproductive technologies. Some unique characteristics common to these species included the presence of a vaginal closure membrane and a lobulated placenta with a vascular sub-placenta. The capybara had hyperpigmentation of the vagina that was unique to each individual, while the agouti and paca had accessory corpora lutea, in addition to the main one. Some reproductive technologies have been used, with attempts at estrous induction and synchronization taking place within the past five years. Even though most work has been done over the past twenty years, there is still a dearth of information.

Highlights

Hystricomorphic rodents belong to the suborder of Hystricomorpha, which refers to one of the four types of rodent skulls based on the nature of their zygomasseteric system, whereby the anterior part of the masseter medialis runs from the medial side of the orbit through an enlarged infraorbital foramen and to the lateral surface of the rostrum and in extreme cases, such as in the capybara (Hydrochoerus spp.), its origin extends as far forward as the pre-maxilla [1,2].Neo-tropical hystricomorphic rodents, such as the agouti (Dasyprocta leporina), capybara (Hydrochoerus hydrochaeris), and paca (Cuniculus paca), possess the potential for domestication and are of importance as they serve as game species, in addition to their ecological roles—such as scatter-hoarders [3–7]
The anatomy of the female reproductive system of all three neo-tropical hystricomorphic rodents showed many similarities, which were consistent with the typical mammalian female reproductive tract
All three species had vaginal closure membranes, which could aid in differentiating the phases of the estrous cycle

Summary

Introduction

Hystricomorphic rodents belong to the suborder of Hystricomorpha, which refers to one of the four types of rodent skulls based on the nature of their zygomasseteric system, whereby the anterior part of the masseter medialis runs from the medial side of the orbit through an enlarged infraorbital foramen and to the lateral surface of the rostrum and in extreme cases, such as in the capybara (Hydrochoerus spp.), its origin extends as far forward as the pre-maxilla [1,2].Neo-tropical hystricomorphic rodents, such as the agouti (Dasyprocta leporina), capybara (Hydrochoerus hydrochaeris), and paca (Cuniculus paca), possess the potential for domestication and are of importance as they serve as game species, in addition to their ecological roles—such as scatter-hoarders [3–7]. Studies defining the age of puberty in females are lacking, Guimarães et al [18] showed that, under the male effect, puberty in D. prymnolopha was attained at nine months They exhibit a continuous polyestrous cycle [19], with an estrous cycle varying among the different species; 34.2 ± 2.1 days in D. aguti [20], 30.69 ± 4.65 days [19] and 29.94 ± 6.77 days [21] in D. prymnolopha, and 28.2 ± 0.7 days in D. leporina, [22]. These rodents have a gestation period of 103–104 days [19,23], with an average litter size of 1.7–2 precocial young [24–26]. After expulsion of the fetus, the fetal membranes and placenta were consumed by the mother [28]

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Conclusion