Maternal Pouch Research Articles

Characterisation of the koala (Phascolarctos cinereus) pouch microbiota in a captive population reveals a dysbiotic compositional profile associated with neonatal mortality

BackgroundCaptive koala breeding programmes are essential for long-term species management. However, breeding efficacy is frequently impacted by high neonatal mortality rates in otherwise healthy females. Loss of pouch young typically occurs during early lactation without prior complications during parturition and is often attributed to bacterial infection. While these infections are thought to originate from the maternal pouch, little is known about the microbial composition of koala pouches. As such, we characterised the koala pouch microbiome across the reproductive cycle and identified bacteria associated with mortality in a cohort of 39 captive animals housed at two facilities.ResultsUsing 16S rRNA gene amplicon sequencing, we observed significant changes in pouch bacterial composition and diversity between reproductive time points, with the lowest diversity observed following parturition (Shannon entropy — 2.46). Of the 39 koalas initially sampled, 17 were successfully bred, after which seven animals lost pouch young (overall mortality rate — 41.18%). Compared to successful breeder pouches, which were largely dominated by Muribaculaceae (phylum — Bacteroidetes), unsuccessful breeder pouches exhibited persistent Enterobacteriaceae (phylum — Proteobacteria) dominance from early lactation until mortality occurred. We identified two species, Pluralibacter gergoviae and Klebsiella pneumoniae, which were associated with poor reproductive outcomes. In vitro antibiotic susceptibility testing identified resistance in both isolates to several antibiotics commonly used in koalas, with the former being multidrug resistant.ConclusionsThis study represents the first cultivation-independent characterisation of the koala pouch microbiota, and the first such investigation in marsupials associated with reproductive outcomes. Overall, our findings provide evidence that overgrowth of pathogenic organisms in the pouch during early development is associated with neonatal mortality in captive koalas. Our identification of previously unreported, multidrug resistant P. gergoviae strains linked to mortality also underscores the need for improved screening and monitoring procedures aimed at minimising neonatal mortality in future.2x5HUzrydQWXd3d2iYrm8oVideo

Pouch brooding marsupial frogs transfer nutrients to developing embryos.

Marsupial frogs have a unique reproductive mode in which females carry eggs enclosed in a sealed dorsal brood pouch. While most anurans are considered to be oviparous with lecithotrophic eggs, the extensively vascularized membrane of the brood pouch in marsupial frogs suggests potential opportunities for nutrient transfer. We tested for matrotrophy in the live-bearing Gastrotheca excubitor (Hemiphractidae), through feeding insects labelled with a 13C-fatty acid and a 15N-amino acid to brooding marsupial frogs. We observed significant increases of δ13C and δ15N in both maternal pouch tissues and embryos, suggesting nutrient transfer. Embryo dry mass also increased with developmental stage, providing further direct evidence for matrotrophy. These results suggest that in addition to gas exchange, the vascularized brood pouch membrane of G. excubitor also enables maternal nutrient transfer. This finding revealed a suspected but untested trait in the evolution of parental care in marsupial frogs, in contrast to previous work on Gastrotheca species that release tadpoles, and suggests greater complexity in reproductive and provisioning modes than previously thought.

Mothers’ Experiences of Kangaroo Mother Care During Hospitalization of Their Preterm Babies at an Academic Hospital in Johannesburg

Kangaroo mother care (KMC) implies placing the newborn pre-term baby in intimate skin-to-skin contact with the mother's chest and abdomen coupled with frequent and preferably exclusive breast-feeding. This is similar to marsupial care-giving, where the premature baby is kept warm in the maternal pouch and close to the breasts for unlimited feeding. KMC has emerged as a non-conventional low cost method for newborn care that provides warmth, touch, and security to the newborn and is believed to confer significant survival benefit. The purpose of this study was to understand the mothers lived experience and perception towards 24-hour Kangaroo Mother Care (KMC) during hospitalization of their preterm babies. Phenomenological study methods were applied through in-depth unstructured interviews, on purposefully selected participants. Their lived experience was analyzed using Collaizzi’s steps to phenomenological data analysis. Data analysis revealed three major themes: (a) “it is a bond between me and my child” (b) nurse-parent interaction, and (c) “it is tiring and exhaustive”. The study found that all the mothers in spite of exhaustion, reported high level of satisfaction with KMC because it allowed them to be closer to their babies, hence giving them the opportunity to observe their growth and became fully involved in the care. The excellent nurse-mothers’ interaction reinforced the KMC concept in care of preterm babies and was rated significant in the transition period of motherhood. The interaction enabled mothers to shift from passive observers to active participants in the care of the preterm babies. KMC was additionally noted to have provided a comforting and warm environment for the babies, thus enabling them to grow faster via weight gains and this in turn increased maternal satisfaction. Recommendation for further research preferably using quantitative methods to establish relationship between production of breast milk and the use of KMC is envisaged. The principle of 24-hour KMC should also be incorporated and emphasized in all levels of preterm baby care hospitals and educational training as this practice has been found to have numerous benefits both to the mothers and to their preterm babies.

Vestibular development in marsupials and monotremes

The young of marsupials and monotremes are all born in an immature state, followed by prolonged nurturing by maternal lactation in either a pouch or nest. Nevertheless, the level of locomotor ability required for newborn marsupials and monotremes to reach the safety of the pouch or nest varies considerably: some are transferred to the pouch or nest in an egg (monotremes); others are transferred passively by gravity (e.g. dasyurid marsupials); some have only a horizontal wriggle to make (e.g. peramelid and didelphid marsupials); and others must climb vertically for a long distance to reach the maternal pouch (e.g. diprotodontid marsupials). In the present study, archived sections of the inner ear and hindbrain held in the Bolk, Hill and Hubrecht collections at the Museum für Naturkunde, Berlin, were used to test the relationship between structural maturity of the vestibular apparatus and the locomotor challenges that face the young of these different mammalian groups. A system for staging different levels of structural maturity of the vestibular apparatus was applied to the embryos, pouch young and hatchlings, and correlated with somatic size as indicated by greatest body length. Dasyurids are born at the most immature state, with the vestibular apparatus at little more than the otocyst stage. Peramelids are born with the vestibular apparatus at a more mature state (fully developed semicircular ducts and a ductus reuniens forming between the cochlear duct and saccule, but no semicircular canals). Diprotodontids and monotremes are born with the vestibular apparatus at the most mature state for the non-eutherians (semicircular canals formed, maculae present, but vestibular nuclei in the brainstem not yet differentiated). Monotremes and marsupials reach the later stages of vestibular apparatus development at mean body lengths that lie within the range of those found for laboratory rodents (mouse and rat) reaching the same vestibular stage.

Kangaroo Mother Care: A Simple Method to Care for Low-Birth-Weight Infants in Developing Countries

Kangaroo Mother Care (KMC) is an effective way to meet baby's needs for warmth, breastfeeding, protection from infection, stimulation, safety and love. Mother acts as an incubator as kangaroo and put low birth infant vertically in between the chest for warming. The term kangaroo care is derived from practical similarities to marsupial care-giving. The premature infant is kept warm in the maternal pouch and is close to the breasts for unlimited feeding. It provides an alternative to incubator care, without separation from the mother. The importance of KMC in low- and middle-income countries has been highlighted as a contributing factor to the achievement of the Millennium Development Goal 4 that targets a reduction by two-thirds of under-five mortality rates from 1990 to 2015. This programme is mediated by humoral, autonomic and somatic behaviours, expressed ultimately as innate competency in breastfeeding behaviours. It is simple, acceptable to mothers and can be continued at home.DOI: http://dx.doi.org/10.3329/jssmc.v5i1.16256 J Shaheed Suhrawardy Med Coll, 2013;5(1):49-54

Development of the Cerebellum in the Platypus (Ornithorhynchus anatinus) and Short-Beaked Echidna (Tachyglossus aculeatus)

The monotremes are a unique group of mammals whose young are incubated in a leathery-shelled egg and fed with milk from teatless areolae after hatching. As soon as they hatch, monotreme young must be able to maneuver around the nest or maternal pouch to locate the areolae and stimulate milk ejection. In the present study, the embryological collections at the Museum für Naturkunde, Berlin, have been used to follow the development of the monotreme cerebellum through incubation and lactational phases, to determine whether cerebellar circuitry is able to contribute to the coordination of locomotion in the monotreme hatchling, and to correlate cerebellar development with behavioral maturation. The structure of the developing monotreme cerebellum and the arrangement of transitory neuronal populations are similar to those reported for fetal and neonatal eutherians, but the time course of the key events of later cerebellar development is spread over a much longer period. Expansion of the rostral rhombic lip and formation of the nuclear and cortical transitory zones occurs by the time of hatching, but it is not until after the end of the first post-hatching week that deep cerebellar neurons begin to settle in their definitive positions and the Purkinje cell layer can be distinguished. Granule cell formation is also prolonged over many post-hatching months and the external granular layer persists for more than 20 weeks after hatching. The findings indicate that cerebellar circuitry is unlikely to contribute to the coordination of movements in the monotreme peri-hatching period. Those activities are most likely controlled by the spinal cord and medullary reticular formation circuitry.

Developmental changes in the electroencephalogram and responses to a noxious stimulus in anaesthetized tammar wallaby joeys (Macropus eugenii eugenii)

The tammar wallaby joey is born extremely immature and most of its neurological development occurs in the maternal pouch. It is not known at what in-pouch age functions such as conscious sensory perception commence. We determined the electroencephalographic (EEG) responses to noxious stimulation in lightly anaesthetized tammar wallaby joeys. Baseline median (F50) and spectral edge (F95) frequencies, total power (Ptot) and frequency spectra between 1 and 30 Hz of the EEG power spectrum were determined. Joeys aged less than 127 days showed little or no EEG activity. Prolonged periods of spontaneous EEG activity were present by 142 days. This activity increased, as did the power in all frequencies, while the duration of any intervening isoelectric periods decreased with increasing in-pouch age. EEG responses to a noxious stimulus (toe clamping) changed with increasing in-pouch age as there was no response from joeys aged 94-127 days (no EEG), a minimal decrease in the F50 in those aged between 142 and 181 days (P = 0.052) and a greater decrease in the F50 in those aged between 187 and 261 days (P < 0.001). The pattern of these changes, which presumably reflects anatomical and functional maturation of the cerebral cortex, is similar to, but develops more slowly than, that reported in the rat. The opening of the eyes and development of the pelage are discussed as markers of when brain development may be sufficient for joeys to consciously perceive noxious sensations including pain.

An observational study of the microbiome of the maternal pouch and saliva of the tammar wallaby, Macropus eugenii, and of the gastrointestinal tract of the pouch young

Marsupial mammals, born in an extremely atricial state with no functional immune system, offer a unique opportunity to investigate both the developing microbiome and its relationship to that of the mother and the potential influence of this microbiome upon the development of the immune system. In this study we used a well-established marsupial model animal, Macropus eugenii, the tammar wallaby, to document the microbiome of three related sites: the maternal pouch and saliva, and the gastrointestinal tract (GIT) of the young animal. We used molecular-based methods, targeting the 16S rDNA gene to determine the bacterial diversity at these study sites. In the maternal pouch, 41 unique phylotypes, predominantly belonging to the phylum Actinobacteria, were detected, while in the saliva, 48 unique phylotypes were found that predominantly belonged to the phylum Proteobacteria. The GIT of the pouch young had a complex microbiome of 53 unique phylotypes, even though the pouch young were still permanently attached to the teat and had only been exposed to the external environment for a few minutes immediately after birth while making their way from the birth canal to the maternal pouch. Of these 53 phylotypes, only nine were detected at maternal sites. Overall, the majority of bacteria isolated were novel species (<97 % identity to known 16S rDNA sequences), and each study site (i.e. maternal pouch and saliva, and the GIT of the pouch young) possessed its own unique microbiome.

Kangaroo mother care-an alternative to conventional care

The term kangaroo mother care (KMC) is derived from practical similarities to marsupial care-giving, i.e., the premature infant is kept warm in the maternal pouch and close to the breasts for unlimited feeding. It is a gentle and effective method that avoids agitation routinely experienced in a busy ward with preterm infants. An important main stay of kangaroo mother care is breastfeeding encouragement. Observational studies have shown reduction in mortality after institution of KMC. Preterm babies exposed to skin to skin contact showed a better mental development and better results in motor tests. It also improves thermal care. All stable LBW babies are candidate for KMC. Often this is desirable, until the baby's gestation reaches term or the weight is around 2500 g. The mother and family members are encouraged to take care of the baby in KMC and should be counseled to come for follow-up visits regularly.

BRIEF COMMUNICATION: Histology of the pouch epithelium and the mammary glands during chemically induced oestrus in the brushtail possum (Trichosurus vulpecula)

Changes in the epithelium of the maternal pouch and the mammary gland of brushtail possums (Trichosurus vulpecula) were examined after animals were treated to induce ovulation with follicle-stimulating hormone (FSH), luteinizing hormone (LH), pregnant mares' serum gonadotrophin (PMSG) and oestradiol. The mammary glands were similar in appearance to those described in eutherian mammals and in previous studies on other marsupials. Exposure of possums to these compounds, particularly PMSG, appeared to result in changes in the mammary glands that could be associated with milk/secretion production. In contrast, the pouch epithelium had a similar histological appearance to that of epithelium from other parts of the body regardless of whether the animal was exposed to stimulants. These preliminary observations are discussed in the context of the purported role of the pouch epithelium and the mammary gland in production of secretions at oestrus and provision of immunological protection to the neonatal marsupial.

Urea is Necessary for the Culture of Embryos of the Marsupial Frog Gastrotheca riobambae, and is Tolerated by Embryos of the Aquatic Frog Xenopus laevis: (ureotelism/urea concentration in frog blood/culture of frog embryos/mesoderm induction).

Urea was found in the capsular fluid that bathes Gastrotheca riobambae embryos during incubation in the maternal pouch. The urea concentration in this fluid is higher than in blood from the mother, indicating that urea is accumulated by the embryo during the period of maternal incubation. Gastrotheca tadpoles tolerate up to 500 mM urea with 86% survival after 24 hours and die in solutions of 0.5 mM ammonia. These findings suggest that urea plays a role in the adaptation of G. riobambae embryos to the conditions of water stress within the maternal pouch. To improve the in vitro culture conditions of early embryos taken from the maternal pouch, a saline solution that contains urea was designed (GRS). GRS plus 30 mM urea was used for the culture of cleavage to the neurula stage embryos of G. riobambae. During organogenesis, the urea concentration was raised to 60 mM. Early embryos of Xenopus laevis tolerate urea, and in addition, no inducing effects of urea have been detected in animal cap explants of Xenopus.

Oogenesis in the egg-brooding frog Gastrotheca riobambae produces large oocytes with fewer nucleoli and low RNA content in comparison to Xenopus laevis

The dissimilarities between oocytes of the eggbrooding frog, Gastrotheca riobambae, and Xenopus laevis suggest that oogenesis is modified according to the mode of reproduction. Oocytes of G. riobambae are large, yolky, and measure about 3 mm in diameter. In spite of the large oocyte size of Gastrotheca, the amplification of ribosomal genes, the number of nucleoli, and the amount of 18S and 28S rRNA are lower than in Xenopus oocytes. In Gastrotheca, the lower RNA content of oocytes is associated with a slow rate of development. A prolonged period of development is possible due to the protection given by the maternal pouch.

Postnatal changes in blood respiratory characteristics in an American opossum ( Didelphis virginiana)

The oxygen affinity of opossum blood changes in the postnatal period. The youngest opossums studied were 53 days of age (dated from the day of transit from vagina to pouch) and still confined to the maternal pouch: they had a blood P 50 of 32.6 ± 2.9 mm Hg. The blood P 50 value then increased significantly, in two steps. First, while the young were still in the pouch, blood P 50 rose secondary to a rise in the concentration of 2,3-diphosphoglycerate (DPG). Blood P 50 and DPG concentration then remained stable until the animals left the maternal pouch, when DPG rose again, causing a further increment in the blood P 50 which peaked at 48.7 ± 4.5 mm Hg in animals 148 days old. Blood P 50 subsequently decreased significantly, reaching the adult value (42.0 ± 1.9 mm Hg) at about 250 days.

The growth‐stages of the pouch‐young of the Native Cat (Dasyurus viverrinus) together with observations on the anatomy of the new‐born young.*

Summary.The biology of the pouch‐young (mammary foetus) is considered in a graded series of stages of Dasyurus commencing with the new‐born, still unattached young and ending with the fully developed animal at the time it leaves the maternal pouch (at the age of 4 to 4 months) and capable of fending for itself. The series has been divided for convenience into seventeen stages, labelled A‐P, and the growth, external appearances and eruption of teeth has been fully considered.The problem of the migration of new‐born young to the pouch, their attachment to the nipples, and the mode of lactation and its duration have been considered, together with some comment of the supposed mammary compressor action of the cremaster muscles.The internal structure of the new‐born Dasyurus has been described in detail, special emphasis being laid on the precocious development of certain structures which are considered necessary adaptational machinery for the insurance of survival of the young in its unusual environment and more particularly those features required for the sole purpose of ensuring its safe arrival in the pouch, its becoming attached to a nipple and the certitude of its receipt of milk without hindrance to its respiration.Notable at birth are (i) the relatively advanced state of the fore‐limbs, (ii) the presence of deciduous claws upon the manual digits and their later replacement by definitive claws, (iii) the presence of the oral shield as a specialization upon the muzzle, (iv) the unique cervical swelling, (v) special features of the tongue and larynx, with the intranasal epiglottis (vi) the reptilian state of the lungs, (vii) the advanced condition of the stomach and duodenum compared with the rest of the gut, (viii) the state of development of brain and sense organs, the olfactory parts being especially forward in development, together with those parts of the nervous system necessary for controlling the movements of the fore‐limb, sucking and respiratory movements, (ix) the indifferent state of the gonads.Throughout comparison has been made with the new‐born of other marsupials, so far as these are known, and features common to them all or peculiar to Dasyurus have been pointed out.

Influence of Anti-Anemic Principles upon Size of Erythrocytes of Opossums (Didelphis virginiana) in Maternal Pouch

The red blood cells of the mammalian fetus are constantly larger than those of adults of the same species, and resemble very closely the erythrocytes found in individuals with pernicious anemia.1 It has likewise been shown experimentally that the mean maximal diameter of erythrocytes of newly born rats can be reduced at birth by the administration of concentrated normal gastric juice to the mother during pregnancy.2The inaccessibility of common mammalian fetuses to direct injection made it desirable to devise a scheme by which anti-anemic principles could be injected directly into the developing animals themselves. The opossum (Didelphis virginiana) is suitable for this purpose because intrauterine life lasts only 10.5 ± 1.7 days, after which the immature young live in the maternal pouch for 90 days.3Materials and Methods. Forty-nine immature opossums, varying in crown-rump lengths from 5.5 to 7.0 cm, were used in these experiments. Twenty were injected over periods varying from 3 to 13 days with 0.8 to 2...