Cellular Components of the Milk of the Tammar Wallaby (Macropus eugenii)

1997 ◽  
Vol 45 (4) ◽  
pp. 423 ◽  
Author(s):  
L. Young ◽  
K. Basden ◽  
D. W. Cooper ◽  
E. M. Deane
Keyword(s):  
Mammary Gland ◽  
Mononuclear Cells ◽  
Tammar Wallaby ◽  
Mammary Glands ◽  
Cell Type ◽  
Phagocytic Cells ◽  
Macropus Eugenii ◽  
Predominant Cell Type ◽  
Cellular Components

The cellular components of colostrum and milk of the tammar wallaby (Macropus eugenii) have been investigated over the period of oestrus, lactation and weaning. Macrophages, neutrophils, lymphocytes and other vacuolated mononuclear cells were identified. The total number and diversity of cells were higher in colostral secretions and in secretions from post-lactational mammary glands. Neutrophils were the predominant cell type in early secretions. Macrophages were more prevalent in the milk of animals that no longer had young attached to the teat. These observations are consistent with suggestions that phagocytic cells play a role in post-lactational repair of the mammary gland but also suggest that non-specific phagocytic protection plays a role in protection of the neonatal marsupial.

PROLACTIN RECEPTORS IN THE MAMMARY GLAND, CORPUS LUTEUM AND OTHER TISSUES OF THE TAMMAR WALLABY, MACROPUS EUGENII

1979 ◽  
Vol 83 (1) ◽  
pp. 79-89 ◽  
Author(s):  
C. SERNIA ◽  
C. H. TYNDALE-BISCOE
Keyword(s):  
Mammary Gland ◽  
Corpus Luteum ◽  
Specific Binding ◽  
Tammar Wallaby ◽  
Binding Activity ◽  
Breeding Cycle ◽  
Macropus Eugenii ◽  
Lactating Mammary Gland ◽  
The Mean ◽  
Ovine Prolactin

SUMMARY Specific binding of radio-iodinated ovine prolactin to subcellular tissue fractions of the tammar wallaby (Macropus eugenii) was investigated. Specific binding was found, in order of decreasing binding activity, in the lactating mammary gland, corpus luteum, corpus albicans, adrenal gland and ovary. Specific binding was absent in kidney, liver, brain and inactive mammary gland. The mean association constant (Ka at 23 °C) was determined as 0·90 × 109, 2·20 × 109, 2·44 × 109, 3·38 × 109 and 10·98 × 1091/mol for mammary gland, adrenal, corpus albicans, corpus luteum and ovary respectively. The mean receptor concentration (N) varied from 92·87 × 10−14 mol/mg protein for the mammary gland to 1·03 × 10−14 mol/mg protein for the ovary. The concentration in the corpus luteum varied between tissue pools collected at different times of the annual breeding cycle. The specificity for prolactin was shown in the mammary gland and corpus luteum by the failure of ovine FSH, LH, GH and TSH to displace 125I-labelled ovine prolactin, whereas it was displaced readily by both ovine and bovine prolactin.

scholarly journals A novel whey protein synthesized only in late lactation by the mammary gland from the tammar (Macropus eugenii)

1987 ◽  
Vol 241 (3) ◽  
pp. 899-904 ◽  
Author(s):  
K R Nicholas ◽  
M Messer ◽  
C Elliott ◽  
F Maher ◽  
D C Shaw
Keyword(s):  
Mammary Gland ◽  
Amino Acid ◽  
Whey Protein ◽  
Sequence Data ◽  
Protein A ◽  
Gel Filtration ◽  
Tammar Wallaby ◽  
Exchange Chromatography ◽  
Macropus Eugenii ◽  
Apparent Homogeneity

A major whey protein which appears in milk from the tammar wallaby (Macropus eugenii) only during the second half of lactation (late lactation protein-A, LLP-A) was purified to apparent homogeneity by ion-exchange chromatography and gel filtration. An Mr of 21,600 +/- 2000 was calculated from its amino acid composition. A computer-based comparison of the sequence of the first 69 amino acid residues with the Atlas of Protein Sequence data base showed no significant homology with known proteins. Antiserum to LLP-A was prepared in rabbits, and single radial immunodiffusion was used to measure the amounts of LLP-A in milk during the first 40 weeks of lactation. LLP-A was first detected at 26 weeks; thereafter its concentration increased abruptly, to reach a maximum of 26 g/l at approx. 36 weeks of lactation. Explants prepared from mammary gland biopsies at 20 and 35 weeks of lactation were exposed to [3H]amino acids for 8 h; immunoprecipitation of tissue extracts showed that, whereas the rate of casein synthesis was the same at both stages of lactation, LLP-A was synthesized only by the 35-week mammary gland.

Cloning, cDNA analysis and prolactin-dependent expression of a marsupial alpha-lactalbumin

1990 ◽  
Vol 2 (6) ◽  
pp. 693 ◽  
Author(s):  
C Collet ◽  
R Joseph ◽  
K Nicholas
Keyword(s):  
Mammary Gland ◽  
Protein Conformation ◽  
Northern Blot Analysis ◽  
Tammar Wallaby ◽  
Amino Acid Residues ◽  
Macropus Eugenii ◽  
Cdna Analysis ◽  
Maximal Induction ◽  
Almost All ◽  
Alpha Lactalbumin

The gene for alpha-lactalbumin has been cloned from a tammar wallaby (Macropus eugenii) mammary gland cDNA library. Tammar alpha-lactalbumin has approximately 50 and 30% homology to the alpha-lactalbumins of eutherians at the levels of nucleotide and protein sequence respectively. Comparison of the inferred tammar polypeptide sequence with the sequence of the eutherian proteins reveals extensive divergence at almost all of the non-essential amino acid residues. However, the hydropathy plots of the tammar protein are almost identical to those of eutherian alpha-lactalbumins, suggesting that protein conformation is conserved. The tammar gene encodes a transcript of approximately 975 bases. Northern blot analysis of hormone-stimulated mammary gland explants shows that maximal induction of alpha-lactalbumin mRNA is dependent on prolactin and that expression is not modulated by other hormones that play a role in the initiation of lactation in eutherians.

Cellular composition of the late milk of the koala (Phascolarctos cinereus)

2001 ◽  
Vol 49 (2) ◽  
pp. 195 ◽  
Author(s):  
L. J. Young ◽  
E. M. Deane
Keyword(s):  
Epithelial Cells ◽  
Mononuclear Cells ◽  
Tammar Wallaby ◽  
Polymorphonuclear Neutrophil ◽  
Cellular Composition ◽  
Phascolarctos Cinereus ◽  
Macropus Eugenii

The changes in cellular composition of the milk of the koala (Phascolarctos cinereus) have been investigated in late lactation and after the loss of pouch and back young. During lactation, the polymorphonuclear neutrophil was the most frequently observed cell. After loss or removal of the young, macrophages and foamy epithelial cells were detected in moderate to high numbers. In one animal, mammary secretions containing lymphocytes and unidentifiable, immature mononuclear cells continued for 120 days after the loss of pouch young. These observations of cellular composition of late- and post-lactation secretions are consistent with reports from a number of eutherian mammals and also with another marsupial, the tammar wallaby (Macropus eugenii).

scholarly journals 282.Differential expression of the relaxin receptor (LGR7) in the mammary apparatus of the lactating tammar wallaby (Macropus eugenii)

2004 ◽  
Vol 16 (9) ◽  
pp. 282
Author(s):  
J. Gwyther ◽  
H. M. Gehring ◽  
L. J. Parry
Keyword(s):  
Gene Expression ◽  
Mammary Gland ◽  
Peptide Hormone ◽  
Tammar Wallaby ◽  
Mammary Glands ◽  
Taqman Probe ◽  
Amino Acid Homology ◽  
Different Ages ◽  
Thermal Cycler ◽  
Relaxin Receptor

Growth and development of the mammary apparatus (nipple and mammary gland) are important aspects of lactation. Macropodid marsupials can suckle young of two different ages simultaneously, a phenomenon known as asynchronous lactation. As a result, the type of milk produced and the structure of the two mammary glands supporting young of different ages vary considerably. A role for the peptide hormone relaxin in lactation has been demonstrated in relaxin receptor (LGR7)-deficient mice, which fail to deliver milk to their offspring due to impaired nipple development (1). This study investigated the distribution of LGR7 in the different mammary glands and nipples during asynchronous lactation in the tammar wallaby. The specific aim was to determine if the age of the pouch young influences LGR7 gene expression. Tissues were collected from the mammary apparatus sustaining the neonate and an older pouch young in the same mother, between Days 0 and 21 of lactation (n = 5/stage). A partial sequence (250-bp) of the tammar LGR7 was first obtained from a region close to the N-terminus of the soluble ectodomain, with 82% amino acid homology compared to the human LGR7 sequence. LGR7 gene expression was then measured by quantitative-PCR, using a TaqMan probe in the Opticon 2 thermal cycler (MJ Research, GeneWorks). Expression of LGR7 was upregulated in both the nipple and mammary gland supporting the neonate between 5 and 11 days after birth. There was no difference in LGR7 expression between these two tissues. However, LGR7 mRNA concentrations were significantly (P < 0.05: paired t-test) higher in the mammary apparatus supporting the neonate compared with that of the older young. These data suggest that a local stimulus, such as the continuous sucking by the neonate, may influence LGR7 expression in the mammary apparatus. (1) Krajnc-Franken et al. (2004) Mol. Cell. Biol. 24, 687–696.

164. THE IMPRINT STATUS AND EXPRESSION OF INS IN THE TAMMAR WALLABY, MACROPUS EUGENII

2009 ◽  
Vol 21 (9) ◽  
pp. 82
Author(s):  
J. M. Stringer ◽  
G. Shaw ◽  
A. Pask ◽  
M. B. Renfree
Keyword(s):  
Mammary Gland ◽  
Genomic Imprinting ◽  
Direct Sequencing ◽  
Tammar Wallaby ◽  
Epigenetic Mechanism ◽  
Macropus Eugenii ◽  
Parental Allele ◽  
Absolute Requirement ◽  
Lactation Phase

Genomic imprinting is an epigenetic mechanism that differentially regulates the expression of certain genes, resulting in expression from only one parental allele. It is presumed to have first evolved after the divergence of therian mammals from the monotremes. One imprinted gene, INS is maternally imprinted (paternally expressed) in the eutherian and marsupial yolk sac1,2. INS encodes the precursor to the hormone insulin, which regulates carbohydrate metabolism and has a role in cell growth and, by regulating amino acid and fatty acid transporters, protein synthesis. In rats, mice and several other mammals insulin, in addition to cortisol and prolactin, is an absolute requirement for the onset of lactation and the synthesis of milk3. As imprinting plays an important role in regulating nutrition and growth the role of imprinted genes in the placenta has been the focus for imprinting research. Since the mammary gland provides a critical source of nutrition for the neonate in all mammals it is possible that genomic imprinting may have developed and been maintained in this organ. Given that marsupials deliver tiny, altricial young, it is in the relatively long and complex lactation phase where the mother has most control of the young's growth. Therefore, there may be greater selection for genomic imprinting in the marsupial mammary gland than in the eutherian mammary gland. This study examined the expression and the imprint status of INS in the mammary gland and neonatal tissues of the tammar wallaby, Macropus eugenii. INS expression was detected using PCR and direct sequencing provides evidence of INS imprinting in the mammary gland. This is the first study to identify imprinting in the mammary gland of a marsupial and the first to identify INS imprinting outside of the yolk sac.

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