Talk:Guinea Pig Development
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Cite this page: Hill, M.A. (2020, January 23) Embryology Guinea Pig Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Talk:Guinea_Pig_Development
External Genital Development, Urethra Formation, and Hypospadias Induction in Guinea Pig: A Double Zipper Model for Human Urethral Development
Urology. 2018 Mar;113:179-186. doi: 10.1016/j.urology.2017.11.002. Epub 2017 Nov 16.
Wang S1, Shi M1, Zhu D2, Mathews R3, Zheng Z4.
OBJECTIVE: To determine whether the guinea pig phallus would be an appropriate model of human penile development, we characterized the embryology and sexual differentiation of guinea pig external genitalia and attended to induce hypospadias in males and tubular urethra formation in females pharmacologically. MATERIALS AND METHODS: The external genitalia of guinea pig were collected from genital swelling initiation to newborn stages, and scanning electronic microscopy and histology were performed to visualize the morphology and structure. Immunohistochemistry was used to determine the androgen receptor localization. Bicalutamide and methyltestosterone were given to pregnant dams to reveal the role and timing of androgen in guinea pig penile masculinization. RESULTS: Canalization and dorsal-to-ventral movement of the urethral canal develops the urethral groove in both sexes, and then the males perform distal-opening-proximal-closing to form tubular urethra. More nuclear-localized androgen receptor is found in proximal genital tubercles of males than in females at (E) 29. Antiandrogen treatment at E26-E30 can cause hypospadias, and methyltestosterone administration at E27-E31 can induce tubular urethra formation in females. CONCLUSION: Fetal development of the guinea pig phallus is homologous to that of humans. Although guinea pig has structures similar to mouse, the urethral groove and the tubular urethra formation are more similar to humans. Antiandrogen treatment causes hypospadias in males and additional androgen induces tubular urethra formation in females. Thus, guinea pig is an appropriate model for further study of cellular and molecular mechanisms involved in distal-opening-proximal-closing in tubular urethra formation and the evaluation of the pathophysiological processes of hypospadias. Published by Elsevier Inc. PMID: 29155192 DOI: 10.1016/j.urology.2017.11.002
Developing guinea pig brain as a model for cortical folding
Dev Growth Differ. 2017 May;59(4):286-301. doi: 10.1111/dgd.12371. Epub 2017 Jun 5.
Hatakeyama J1, Sato H1, Shimamura K1.
Abstract The cerebral cortex in mammals, the neocortex specifically, is highly diverse among species with respect to its size and morphology, likely reflecting the immense adaptiveness of this lineage. In particular, the pattern and number of convoluted ridges and fissures, called gyri and sulci, respectively, on the surface of the cortex are variable among species and even individuals. However, little is known about the mechanism of cortical folding, although there have been several hypotheses proposed. Recent studies on embryonic neurogenesis revealed the differences in cortical progenitors as a critical factor of the process of gyrification. Here, we investigated the gyrification processes using developing guinea pig brains that form a simple but fundamental pattern of gyri. In addition, we established an electroporation-mediated gene transfer method for guinea pig embryos. We introduce the guinea pig brain as a useful model system to understand the mechanisms and basic principle of cortical folding. KEYWORDS: cerebral cortex; cortical folding; electroporation; guinea pig; gyrification PMID: 28585227 DOI: 10.1111/dgd.12371
An ecologically relevant guinea pig model of fetal behavior
Behav Brain Res. 2015 Apr 15;283:175-83. doi: 10.1016/j.bbr.2015.01.047. Epub 2015 Feb 2.
Bellinger SA1, Lucas D1, Kleven GA2.
The laboratory guinea pig, Cavia porcellus, shares with humans many similarities during pregnancy and prenatal development, including precocial offspring and social dependence. These similarities suggest the guinea pig as a promising model of fetal behavioral development as well. Using innovative methods of behavioral acclimation, fetal offspring of female IAF hairless guinea pigs time mated to NIH multicolored Hartley males were observed longitudinally without restraint using noninvasive ultrasound at weekly intervals across the 10 week gestation. To ensure that the ultrasound procedure did not cause significant stress, salivary cortisol was collected both before and after each observation. Measures of fetal spontaneous movement and behavioral state were quantified from video recordings from week 3 through the last week before birth. Results from prenatal quantification of Interlimb Movement Synchrony and state organization reveal guinea pig fetal development to be strikingly similar to that previously reported for other rodents and preterm human infants. Salivary cortisol readings taken before and after sonography did not differ at any observation time point. These results suggest this model holds translational promise for studying the prenatal mechanisms of neurobehavioral development, including those that may result from adverse events. Because the guinea pig is a highly social mammal with a wide range of socially oriented vocalizations, this model may also have utility for studying the prenatal origins and trajectories of developmental disabilities with social-emotional components, such as autism. Copyright © 2015 Elsevier B.V. All rights reserved. KEYWORDS: Cortisol; Fetal movement; Interlimb coordination; Prenatal behavior; Restraint stress
Morphometric analysis of fetal development of Cavia porcellus (Linnaeus, 1758) by ultrasonography-Pilot study
Theriogenology. 2014 Apr 15;81(7):896-900. doi: 10.1016/j.theriogenology.2014.01.004. Epub 2014 Jan 16. Santos J1, Fonseca E2, van Melis J3, Miglino MA4. Author information
Measurements on the growth process and placental development of the embryo and fetuses of Cavia porcellus were carried out using ultrasonography. Embryo, fetus, and placenta were monitored from Day 15 after mating day to the end of gestation. Based on linear and quadratic regressions, the following morphometric analysis showed a good indicator of the gestational age: placental diameter, biparietal diameter, renal length, and crown rump. The embryonic cardiac beat was first detected at an average of 22.5 days. The placental diameter showed constant increase from beginning of gestation then remained to term and presented a quadratic correlation with gestational age (r(2) = 0.89). Mean placental diameter at the end of pregnancy was 3.5 ± 0.23 cm. By Day 30, it was possible to measure biparietal diameter, which followed a linear pattern of increase up to the end of gestation (r(2) = 0.95). Mean biparietal diameter in the end of pregnancy was 1.94 ± 0.03 cm. Kidneys were firstly observed on Day 35 as hyperechoic structures without the distinction of medullar and cortical layers, thus the regression model equation between kidney length and gestational age presents a quadratic relationship (r(2) = 0.7). The crown rump presented a simple linear growth, starting from 15 days of gestation, displaying a high correlation with the gestational age (r(2) = 0.9). The offspring were born after an average gestation of 61.3 days. In this study, we conclude that biparietal diameter, placental diameter, and crown rump are adequate predictive parameters of gestational age in guinea pigs because they present high correlation index. Copyright © 2014 Elsevier Inc. All rights reserved. KEYWORDS: Embryo age, Fetal age, Guinea pig, Pregnancy, Ultrasound
Differential effect of intrauterine hypoxia on caspase 3 and DNA fragmentation in fetal guinea pig hearts and brains
Reprod Sci. 2012 Mar;19(3):298-305. doi: 10.1177/1933719111420883.
Evans LC, Liu H, Thompson LP. Source Department of Obstetrics, Gynecology and Reproductive Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
The aim of this study is to quantify the effect of intrauterine hypoxia (HPX) and the role of nitric oxide (NO) on the apoptotic enzyme, caspase 3, and DNA fragmentation in fetal heart and brain. Hypoxia and NO are important regulators of apoptosis, although this has been little studied in the fetal organs. We investigated the effect of intrauterine HPX on apoptosis and the role of NO in both fetal hearts and brains. Pregnant guinea pigs were exposed to room temperature (N = 14) or 10.5% O₂ (N = 12) for 14 days prior to term (term = 65 days) and administered water or L-N6-(1-iminoethyl)-lysine (LNIL), an inducible nitric oxide synthase (iNOS) inhibitor, for 10 days. Fetal hearts and brains were excised from anesthetized near-term fetuses for study. Chronic HPX decreased pro- and active caspase 3, caspase 3 activity, and DNA fragmentation levels in fetal hearts compared with normoxic controls. L-N6-(1-iminoethyl)-lysine prevented the HPX-induced decrease in caspase 3 activity but did not alter DNA fragmentation levels. In contrast, chronic HPX increased both apoptotic indices in fetal brains, which were inhibited by LNIL. Thus, the effect of HPX on apoptosis differs between fetal organs, and NO may play an important role in modulating these effects.
- adult guinea pig - the malleus and incus are normally found as a single complex.
- mouse - the malleus and incus develop from a single condensation that splits to form the two ossicles.
Joint formation in the middle ear: lessons from the mouse and guinea pig. Amin S, Tucker AS. Dev Dyn. 2006 May;235(5):1326-33. http://www.ncbi.nlm.nih.gov/pubmed/16425222 PMID: 16425222