scholarly journals Opossum milk IgG is from maternal circulation and timing of transfer correlates with neonatal immune development

2019 ◽  
Vol 31 (7) ◽  
pp. 1246 ◽  
Author(s):  
Bethaney D. Fehrenkamp ◽  
Kimberly A. Morrissey ◽  
Robert D. Miller
Keyword(s):  
Milk Composition ◽  
Fc Receptor ◽  
Monodelphis Domestica ◽  
Maternal Circulation ◽  
Immune Development ◽  
Heavy Chains ◽  
Parallel Increase ◽  
Neonatal Immune System ◽  
Changing Patterns ◽  
Marsupial Species

Marsupials, with short gestation times, have more complex and changing patterns of milk composition than eutherians. Maternal immunoglobulins (Ig) that confer immunity on offspring are among the components that change during marsupial lactation. In the present study we quantified the abundance of mammary transcripts encoding Ig heavy chains and their corresponding transporters in the laboratory opossum Monodelphis domestica. IgA transcripts were the most abundant in opossum mammary and, with IgM, increased in abundance linearly from birth to weaning. Similarly, the Fc receptor for IgA, the poly-Ig receptor, also increased in abundance throughout lactation. There were few transcripts for IgG or IgE within the opossum mammaries. This is in contrast with reports for Australian marsupial species. Transcripts for the Neonatal Fc Receptor (FcRN), which transports IgG, were detected throughout lactation, and opossum milk is known to contain IgG. Therefore, milk IgG is likely to be taken from the maternal circulation, rather than resulting from local production. There is a parallel increase in FcRN in the newborn gut that declines around the time when neonates have matured to the point where they can make their own IgG. These results are consistent with a transfer of maternal Ig that is coordinated with the development of the neonatal immune system.

scholarly journals Cortical plasticity following stripe rearing in the marsupialMonodelphis domestica: neural response properties of V1

2017 ◽  
Vol 117 (2) ◽  
pp. 566-581 ◽  
Author(s):  
James C. Dooley ◽  
Michaela S. Donaldson ◽  
Leah A. Krubitzer
Keyword(s):  
Visual System ◽  
Cortical Neurons ◽  
Functional Organization ◽  
Sensory Experience ◽  
Monodelphis Domestica ◽  
Visual Environment ◽  
Visual Response ◽  
Response Properties ◽  
Dependent Plasticity ◽  
Marsupial Species

The functional organization of the primary visual area (V1) and the importance of sensory experience in its normal development have been well documented in eutherian mammals. However, very few studies have investigated the response properties of V1 neurons in another large class of mammals, or whether sensory experience plays a role in shaping their response properties. Thus we reared opossums ( Monodelphis domestica) in normal and vertically striped cages until they reached adulthood. They were then anesthetized using urethane, and electrophysiological techniques were used to examine neuronal responses to different orientations, spatial and temporal frequencies, and contrast levels. For normal opossums, we observed responses to the temporal and spatial characteristics of the stimulus to be similar to those described in small, nocturnal, eutherian mammals such as rats and mice; neurons in V1 responded maximally to stimuli at 0.09 cycles per degree and 2.12 cycles per second. Unlike other eutherians, but similar to other marsupials investigated, only 40% of the neurons were orientation selective. In stripe-reared animals, neurons were significantly more likely to respond to vertical stimuli at a wider range of spatial frequencies, and were more sensitive to gratings at lower contrast values compared with normal animals. These results are the first to demonstrate experience-dependent plasticity in the visual system of a marsupial species. Thus the ability of cortical neurons to alter their properties based on the dynamics of the visual environment predates the emergence of eutherian mammals and was likely present in our earliest mammalian ancestors.NEW & NOTEWORTHY These results are the first description of visual response properties of the most commonly studied marsupial model organism, the short-tailed opossum ( Monodelphis domestica). Further, these results are the first to demonstrate experience-dependent plasticity in the visual system of a marsupial species. Thus the ability of cortical neurons to alter their properties based on the dynamics of the visual environment predates the emergence of eutherian mammals and was likely present in our earliest mammalian ancestors.

Gonadal sex differentiation in the neonatal marsupial, Monodelphis domestica

Development ◽  
1990 ◽  
Vol 109 (3) ◽  
pp. 699-703
Author(s):  
P.J. Baker ◽  
H.D. Moore ◽  
L.M. Penfold ◽  
A.M. Burgess ◽  
U. Mittwoch
Keyword(s):  
Sex Chromosomes ◽  
Tunica Albuginea ◽  
Histological Study ◽  
Sex Differentiation ◽  
In Utero ◽  
Monodelphis Domestica ◽  
Gonadal Differentiation ◽  
Marsupial Species

A quantitative and histological study of the gonads of newborn grey short-tailed opossums, Monodelphis domestica, is described. The pups were karyotyped, and comparisons were made within litters segregating for XX and XY sex chromosomes. A total of four litters including 25 pups were available. On the day of birth, developing testes were significantly larger than the ovaries of litter mates, and testes could be histologically distinguished by the formation of sex cords and a tunica albuginea. The data suggest that in this marsupial species gonadal differentiation may be initiated in utero.

Entrainment of circadian phase in developing gray short-tailed opossums: mother vs. environment.

1990 ◽  
Vol 259 (3) ◽  
pp. E384
Author(s):  
S A Rivkees ◽  
S M Reppert
Keyword(s):  
Circadian Clock ◽  
Metabolic Activity ◽  
Biological Clock ◽  
Monodelphis Domestica ◽  
Dark Cycle ◽  
Circadian Phase ◽  
Environmental Light ◽  
Circadian Time ◽  
Retinohypothalamic Tract ◽  
Marsupial Species

In a marsupial species, the gray short-tailed opossum (Monodelphis domestica), the suprachiasmatic nuclei (SCN), the site of a circadian clock, are formed postnatally and begin oscillating as a circadian clock on day 20. In this study, we examined how the timing (phase) of the SCN clock in the developing opossum is coordinated to the environmental light-dark cycle. When pups were reared from birth in darkness by intact dams, the circadian phases in SCN metabolic activity (monitored by 2-deoxy-D-[14C]glucose autoradiography) in 27-day-old pups were desynchronized. When pups were reared in a light-dark cycle that was 12 h out of phase with the circadian time of blinded dams, the pattern of SCN metabolic activity on day 20 was rhythmic and in phase with the light-dark cycle but out of phase with the circadian time of the dam. On day 20, retina-mediated light activation of SCN metabolic activity was also demonstrated, and anterograde tract-tracing studies revealed the presence of the retinohypothalamic tract within the SCN. These results show there is no influence of the opossum dam on the timing of the pup's biological clock. Instead, from the inception of the daily rhythm in SCN metabolic activity, its timing is regulated by retina-mediated light-dark entrainment.

scholarly journals Site of binding of mouse IgG2b to the Fc receptor on mouse macrophages.

1979 ◽  
Vol 150 (3) ◽  
pp. 721-726 ◽  
Author(s):  
B Diamond ◽  
B K Birshtein ◽  
M D Scharff
Keyword(s):  
Heavy Chain ◽  
Fc Receptors ◽  
Myeloma Cell ◽  
Fc Receptor ◽  
Heavy Chains ◽  
Mouse Macrophages ◽  
Mouse Myeloma Cell Line ◽  
Ch2 Domain ◽  
A Site ◽  
Mouse Myeloma

Three mouse immunoglobulins with altered heavy chains have been used to study the specificity of the mouse IgG2b Fc receptor on mouse macrophages. These immunoglobulins were synthesized by variant clones derived from the MPC 11, IgG2b-producing mouse myeloma cell line. One variant, whose Fc receptor. A second variant, which makes a short heavy chain lacking the CH3 domain, binds specifically to the IgG2b Fc receptor. The third variant makes a hybrid IgG2b-IgG2a heavy chain whose CH3 domain is enterely IgG2a-like and binds to both IgG2a and IgG2b Fc receptors. These data suggest that the binding of mouse IgG2b immunoglobulins to the mouse macrophage Fc receptor involves a site within the CH2 domain and indicate that immunoglobulins with altered heavy chains are a useful tool to probe Fc receptors.

scholarly journals Rodents and other small mammal reservoirs in plague foci in northeastern Brazil

2017 ◽  
Vol 11 (05) ◽  
pp. 426-430 ◽  
Author(s):  
Erika de Cássia Vieira Da Costa ◽  
Marise Sobreira ◽  
Nilma Cintra Leal ◽  
Alzira Maria Paiva De Almeida
Keyword(s):  
Tissue Sample ◽  
Protein A ◽  
Monodelphis Domestica ◽  
Northeastern Brazil ◽  
Wild Rodents ◽  
Qualitative And Quantitative ◽  
Animal Populations ◽  
In The Wild ◽  
Marsupial Species ◽  
Rodent Populations

Introduction: Plague is an acute, infectious zoonotic disease, primarily of wild rodents and their fleas, that affects humans and other mammals. In Brazil, several plague foci are located in the northeast region. Plague surveillance based on monitoring of rodents was discontinued in 2007, and the current information on rodent populations is unsatisfactory. Our purpose was to update the information on rodents and other small mammals in plague foci in northeastern Brazil. Methodology: Nine surveys in the historically most important northeastern plague areas were conducted in 2013-2015. Results: In this study, 393 animals (13 rodent and four marsupial species) were entrapped. The plague bacterium Yersinia pestis was not detected in tissue sample cultures from the 225 animals that were analyzed. Eighty sera samples were analyzed for anti-F1 antibodies by hemagglutination (HA) and protein A ELISA tests, and all were negative, except for one marsupial, Monodelphis domestica, which was HA positive. Conclusions: Qualitative and quantitative differences in the animal populations were observed in the areas surveyed, and the antibody positive marsupial indicated that plague continues to circulate in the wild.

scholarly journals An X chromosome MicroRNA Cluster in the Marsupial Species Monodelphis domestica

2011 ◽  
Vol 102 (5) ◽  
pp. 577-583 ◽  
Author(s):  
Eric J. Devor ◽  
Lingyan Huang ◽  
Amanda Wise ◽  
Andrew S. Peek ◽  
Paul B. Samollow
Keyword(s):  
X Chromosome ◽  
Monodelphis Domestica ◽  
Microrna Cluster ◽  
Marsupial Species

Placental Alkaline Phosphatase as the Placental IgG Receptor

1992 ◽  
Vol 38 (12) ◽  
pp. 2543-2545 ◽  
Author(s):  
R Makiya ◽  
T Stigbrand
Keyword(s):  
Alkaline Phosphatase ◽  
Dissociation Constant ◽  
Cell Line ◽  
Physiological Role ◽  
Fc Receptor ◽  
Placental Alkaline Phosphatase ◽  
Maternal Circulation ◽  
Endocytic Machinery

Abstract We review data from our studies of the physiological role of placental alkaline phosphatase (PLAP) and report that, in addition to functioning in catalysis, PLAP has the capacity to bind the Fc portion of human IgG. The dissociation constant for the interaction (3.86 mumol/L) indicates that the PLAP-IgG complex probably occurs in vivo. Furthermore, the electrophoretic and immunochemical properties of PLAP are identical to those of the purified placental Fc receptor. This receptor is believed to participate in the transfer of IgG molecules from the maternal circulation to the fetus during pregnancy. Studies with HEp2 cells show that PLAP is necessary for the internalization of IgG molecules. PLAP behaves, at least in this cell line, as an Fc receptor. The presence of large amounts of PLAP in clathrin-coated vesicles prepared from placenta strongly indicates that PLAP is involved in the endocytic machinery in this organ. We conclude that these results, taken together, suggest a novel biological role for PLAP.

scholarly journals Opossum Mammary Maturation as It Relates to Immune Cell Infiltration and Nutritional Gene Transcription

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
B D Fehrenkamp ◽  
R D Miller
Keyword(s):  
Immune Cell ◽  
Transcript Abundance ◽  
Monodelphis Domestica ◽  
Mammary Tissue ◽  
Mammalian Evolution ◽  
Developmental Needs ◽  
Marsupial Species ◽  
Species Specific ◽  
And Behavior

Synopsis The mammary gland has evolved to accommodate the developmental needs of offspring in species-specific ways. This is particularly true for marsupials. Marsupial milk content changes dramatically throughout lactation in ways appearing timed with neonatal ontogeny and behavior. Here we investigate morphological restructuring within the mammaries throughout lactation in the gray short-tailed opossum, Monodelphis domestica. Substantial remodeling of the mammaries occurs throughout the first half of active lactation. It is not until the latter half of lactation that opossum mammaries appear histologically similar to active eutherian mammaries. Noteworthy was the presence of eosinophils in early developing mammary tissue, which correlated with elevated abundance of transcripts encoding the chemokine IL-16. The presence and abundance of whey protein transcripts within the opossum mammaries were also quantified. Whey acidic protein (WAP) transcript abundance peaked in the latter half of lactation and remained elevated through weaning. Minimal transcripts for the marsupial-specific Early and Late Lactation Proteins (ELP/LLP) were detected during active lactation. Elevated abundance of LLP transcripts was only detected prior to parturition. Overall, the results support the role of eosinophils in mammary restructuring appearing early in mammalian evolution, and describe key similarities and differences in nutritional protein transcript abundance among marsupial species.

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