Marsupial milk: a fluid source of nutrition and immune factors for the developing pouch young

2019 ◽  
Vol 31 (7) ◽  
pp. 1252 ◽  
Author(s):  
Elizabeth A. Pharo
Keyword(s):  
Reproductive Strategy ◽  
Tammar Wallaby ◽  
Milk Composition ◽  
Phase 3 ◽  
Fluid Source ◽  
Macropus Eugenii ◽  
Milk Components ◽  
Immunological Factors ◽  
Lactation Cycle ◽  
Australian Marsupial

Marsupials have a very different reproductive strategy to eutherians. An Australian marsupial, the tammar wallaby (Macropus eugenii) has a very short pregnancy of about 26.5 days, with a comparatively long lactation of 300–350 days. The tammar mother gives birth to an altricial, approximately 400 mg young that spends the first 200 days postpartum (p.p.) in its mother’s pouch, permanently (0–100 days p.p.; Phase 2A) and then intermittently (100–200 days p.p.; Phase 2B) attached to the teat. The beginning of Phase 3 marks the first exit from the pouch (akin to the birth of a precocious eutherian neonate) and the supplementation of milk with herbage. The marsupial mother progressively alters milk composition (proteins, fats and carbohydrates) and individual milk constituents throughout the lactation cycle to provide nutrients and immunological factors that are appropriate for the considerable physiological development and growth of her pouch young. This review explores the changes in tammar milk components that occur during the lactation cycle in conjunction with the development of the young.

Mullerian inhibiting substance production and testicular migration and descent in the pouch young of a marsupial

Development ◽  
1988 ◽  
Vol 104 (4) ◽  
pp. 549-556 ◽  
Author(s):  
J.M. Hutson ◽  
G. Shaw ◽  
W.S. O ◽  
R.V. Short ◽  
M.B. Renfree
Keyword(s):  
Tammar Wallaby ◽  
Testicular Descent ◽  
Future Studies ◽  
Macropus Eugenii ◽  
Müllerian Inhibiting Substance ◽  
Sequence Of Events ◽  
Testicular Differentiation ◽  
Testicular Migration ◽  
Australian Marsupial ◽  
Mullerian Inhibiting Substance

The ontogeny of Mullerian inhibiting substance (MIS) production by the developing testis of an Australian marsupial, the tammar wallaby (Macropus eugenii), was determined during pouch life using an organ-culture bioassay of mouse fetal urogenital ridge. This information was related to the morphological events during testicular migration and descent. MIS biological activity was found in testes (but not ovaries or liver) of pouch young from 2 to 85 days of age. MIS production had commenced by day 2, which is within a day of the first gross morphological signs of testicular differentiation. Mullerian duct regression occurred between 10 and 30 days, which partly coincided with testicular migration to the inguinal region and enlargement of the gubernacular bulb (15 to 30 days). These observations are consistent with the hypothesis that MIS may be involved in testicular transabdominal migration. The epididymis commenced development and growth only after the testis had descended through the inguinal ring. This provides no support for the suggestion that the epididymis is involved in testicular descent into the scrotum. The basic sequence of events in post-testicular sexual differentiation in the wallaby is sufficiently similar to that seen in eutherian mammals to make it an excellent experimental model for future studies of testicular differentiation, migration and descent.

Progressive changes in milk protein gene expression and prolactin binding during lactation in the tammar wallaby (Macropus eugenii)

1994 ◽  
Vol 13 (2) ◽  
pp. 117-125 ◽  
Author(s):  
P H Bird ◽  
K A K Hendry ◽  
D C Shaw ◽  
C J Wilde ◽  
K R Nicholas
Keyword(s):  
Gene Expression ◽  
Milk Protein ◽  
Protein Gene ◽  
Tammar Wallaby ◽  
Mammary Tissue ◽  
Phase 2 ◽  
Phase 3 ◽  
Milk Protein Gene ◽  
Macropus Eugenii ◽  
Milk Protein Gene Expression

ABSTRACT Changes in milk protein gene expression and specific prolactin binding were quantified in mammary tissue from the tammar wallaby (Macropus eugenii) at different stages of lactation. The transition from early (phase 2) lactation to late (phase 3) lactation was characterized by the induction of the gene for late lactation protein, a novel whey protein. During the same period, the levels of β-lactoglobulin and β-casein gene expression increased, whereas there was no change in the levels of expression of α-lactalbumin and α-casein genes. Prolactin binding in the mammary gland doubled during the latter half of phase 2 of lactation but declined significantly during the transition to phase 3 of lactation. These changes in prolactin binding resulted from changes in the number of receptors and not from a change in the affinity of the receptor for prolactin. Treatment of membranes with concanavalin A increased the number of prolactin-binding sites by 40% in membranes from phase 2 mammary tissue but decreased binding by 40% in membranes from phase 3 tissue, indicating that significant changes had occurred in the membranes of cells during this period. The tammar wallaby can secrete phase 2 and phase 3 milk from adjacent mammary glands (asynchronous concurrent lactation) and the developmental changes in milk protein gene expression and prolactin binding observed during lactation were reflected in these individual glands. Taken collectively, these findings suggest that mammary development and milk secretion in the tammar wallaby are regulated by both endocrine and local (intramammary) mechanisms.

scholarly journals Maternal Regulation of Milk Composition, Milk Production, and Pouch Young Development During Lactation in the Tammar Wallaby (Macropus eugenii )1

2003 ◽  
Vol 68 (3) ◽  
pp. 929-936 ◽  
Author(s):  
Josephine F. Trott ◽  
Kaylene J. Simpson ◽  
Richard L.C. Moyle ◽  
Cyrma M. Hearn ◽  
Geoffrey Shaw ◽  
...  
Keyword(s):  
Milk Production ◽  
Tammar Wallaby ◽  
Milk Composition ◽  
Macropus Eugenii ◽  
Maternal Regulation

scholarly journals Differential temporal expression of milk miRNA during the lactation cycle of the marsupial tammar wallaby (Macropus eugenii)

BMC Genomics ◽  
2014 ◽  
Vol 15 (1) ◽  
pp. 1012 ◽  
Author(s):  
Vengamanaidu Modepalli ◽  
Amit Kumar ◽  
Lyn A Hinds ◽  
Julie A Sharp ◽  
Kevin R Nicholas ◽  
...  
Keyword(s):  
Tammar Wallaby ◽  
Temporal Expression ◽  
Macropus Eugenii ◽  
Lactation Cycle

Construction of a marsupial bacterial artificial chromosome library from the model Australian marsupial, the tammar wallaby (Macropus eugenii)

2005 ◽  
Vol 53 (6) ◽  
pp. 389 ◽  
Author(s):  
Natasha Sankovic ◽  
Wayne Bawden ◽  
John Martyn ◽  
Jennifer A. M. Graves ◽  
Kurt Zuelke
Keyword(s):  
Bacterial Artificial Chromosome ◽  
Positional Cloning ◽  
Bac Library ◽  
Artificial Chromosome ◽  
Single Copy ◽  
Tammar Wallaby ◽  
Average Insert Size ◽  
Insert Size ◽  
Macropus Eugenii ◽  
Australian Marsupial

With the accelerating recognition of the power of comparative genomics, there is now enormous interest in sequencing the genomes of a broad range of species. Marsupials diverged at an important evolutionary time. The model Australian marsupial, the tammar wallaby (Macropus eugenii), has long been a resource for biological and genetic studies of marsupials, and the availability of a bacterial artificial chromosome (BAC) library will be a valuable resource in these studies. A tammar wallaby BAC library was constructed using pRazorBAC vector. It contains 55 296 clones with an average insert size of 108 kb, representing 2.2 times coverage of the wallaby genome (based on an estimated 2.7 × 109 bp haploid genome size). The library was arrayed in 384-well plates, and spotted in duplicate onto nylon membranes. Screening these membranes has yielded clones containing 34 single-copy genes distributed over the genome, while it failed for only one gene. Each probe isolated 1–12 BAC clones and, to date, no chimeric clones have been found. This BAC library will constitute an invaluable resource for creating physical maps, positional cloning of genes and other sequences in the tammar wallaby, as well as comparative mapping studies in mammals.

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