Dana A. Thomsen

Aboriginal perspectives on kangaroo management in South Australia

Kangaroos are culturally significant to Aboriginal people but Aboriginal people are generally not involved in kangaroo management or in the kangaroo industry. Our research has provided the first opportunity for Aboriginal people in South Australia to present their perspectives on the commercial harvest of kangaroos. Research methods were qualitative, involving consultations with authoritative Aboriginal people about their perspectives, aspirations, and how they see their rights and interests in relation to the commercial harvest of kangaroos. We found diverse views on this topic from Aboriginal research participants. For some Aboriginal people, strict cultural protocols preclude any involvement in the commercial harvest, but for people from other regions where the cultural laws concerning kangaroos are quite different, there is interest in developing enterprises based on kangaroo harvest. Despite the diversity of views about commercial kangaroo harvest, Aboriginal people across South Australia highly value kangaroos, and want to be included in decision-making processes for kangaroo management. There is potential for appropriate engagement of Aboriginal people in kangaroo management through improved communication, greater understanding and respect for the diversity of Aboriginal perspectives and protocols regarding native wildlife.

Social and cultural dimensions of commercial kangaroo harvest in South Australia

Kangaroo management is important to the sustainability of Australia’s rangeland landscapes. The commercial harvest of kangaroos assists in reduction of total grazing pressure in the rangelands and provides the potential for supplementary income to pastoralists. Indeed, the commercial kangaroo industry is considered by natural resource scientists as one of the few rural industry development options with potential to provide economic return with minimal environmental impact. While the biology and population ecology of harvested kangaroo species in Australia is the subject of past and present research, the social, institutional and economic issues pertinent to the commercial kangaroo industry are not well understood. Our research is addressing the lack of understanding of social issues around kangaroo management, which are emerging as constraints on industry development. The non-indigenous stakeholders in kangaroo harvest are landholders, regional management authorities, government conservation and primary production agencies, meat processors, marketers and field processors (shooters) and these industry players generally have little understanding of what issues the commercial harvest of kangaroos presents to Aboriginal people. Consequently, the perspectives and aspirations of Aboriginal people regarding the commercial harvest of kangaroos are not well considered in management, industry development and planning. For Aboriginal people, kangaroos have subsistence, economic and cultural values and while these values and perspectives vary between language groups and individuals, there is potential to address indigenous issues by including Aboriginal people in various aspects of kangaroo management. This research also examines the Aboriginal interface with commercial kangaroo harvest, and by working with Aboriginal people and groups is exploring several options for greater industry involvement. The promotion of better understandings between indigenous and non-indigenous people with interests in kangaroo management could promote industry development through the marketing of kangaroo as not only clean and green, but also as a socially just product.

Maternal and Paternal Genomes Differentially Affect Myofibre Characteristics and Muscle Weights of Bovine Fetuses at Midgestation

Postnatal myofibre characteristics and muscle mass are largely determined during fetal development and may be significantly affected by epigenetic parent-of-origin effects. However, data on such effects in prenatal muscle development that could help understand unexplained variation in postnatal muscle traits are lacking. In a bovine model we studied effects of distinct maternal and paternal genomes, fetal sex, and non-genetic maternal effects on fetal myofibre characteristics and muscle mass. Data from 73 fetuses (Day153, 54% term) of four genetic groups with purebred and reciprocal cross Angus and Brahman genetics were analyzed using general linear models. Parental genomes explained the greatest proportion of variation in myofibre size of Musculus semitendinosus (80–96%) and in absolute and relative weights of M. supraspinatus, M. longissimus dorsi, M. quadriceps femoris and M. semimembranosus (82–89% and 56–93%, respectively). Paternal genome in interaction with maternal genome (P<0.05) explained most genetic variation in cross sectional area (CSA) of fast myotubes (68%), while maternal genome alone explained most genetic variation in CSA of fast myofibres (93%, P<0.01). Furthermore, maternal genome independently (M. semimembranosus, 88%, P<0.0001) or in combination (M. supraspinatus, 82%; M. longissimus dorsi, 93%; M. quadriceps femoris, 86%) with nested maternal weight effect (5–6%, P<0.05), was the predominant source of variation for absolute muscle weights. Effects of paternal genome on muscle mass decreased from thoracic to pelvic limb and accounted for all (M. supraspinatus, 97%, P<0.0001) or most (M. longissimus dorsi, 69%, P<0.0001; M. quadriceps femoris, 54%, P<0.001) genetic variation in relative weights. An interaction between maternal and paternal genomes (P<0.01) and effects of maternal weight (P<0.05) on expression of H19, a master regulator of an imprinted gene network, and negative correlations between H19 expression and fetal muscle mass (P<0.001), suggested imprinted genes and miRNA interference as mechanisms for differential effects of maternal and paternal genomes on fetal muscle.

Rules, Norms and Strategies of Kangaroo Harvest

Kangaroos are a common pool resource harvested for commercial markets that utilise meat and skins. Harvest is regulated by legislation that establishes the formal rules of the kangaroo industry. Our recent research, conducted in South Australia, examined the formal rules of commercial harvest and has also uncovered informal institutions in operation. By analysing data from interviews with landholders (pastoral lease holders), kangaroo harvesters and kangaroo meat processors we found that the formal rules imposed by government regulators are not always congruent with efficient and effective harvest regimes. We have used Crawford and Ostroms (2005) syntax for classifying rules in our examination of the informal institutions fashioned by industry actors. Resource users may not always follow the formal rules of use imposed by government, but when personal livelihoods are at stake they do act to conserve their resource base.

Widespread Differential Maternal and Paternal Genome Effects on Fetal Bone Phenotype at Mid‐Gestation

Parent‐of‐origin–dependent (epi)genetic factors are important determinants of prenatal development that program adult phenotype. However, data on magnitude and specificity of maternal and paternal genome effects on fetal bone are lacking. We used an outbred bovine model to dissect and quantify effects of parental genomes, fetal sex, and nongenetic maternal effects on the fetal skeleton and analyzed phenotypic and molecular relationships between fetal muscle and bone. Analysis of 51 bone morphometric and weight parameters from 72 fetuses recovered at day 153 gestation (54% term) identified six principal components (PC1–6) that explained 80% of the variation in skeletal parameters. Parental genomes accounted for most of the variation in bone wet weight (PC1, 72.1%), limb ossification (PC2, 99.8%), flat bone size (PC4, 99.7%), and axial skeletal growth (PC5, 96.9%). Limb length showed lesser effects of parental genomes (PC3, 40.8%) and a significant nongenetic maternal effect (gestational weight gain, 29%). Fetal sex affected bone wet weight (PC1, p < 0.0001) and limb length (PC3, p < 0.05). Partitioning of variation explained by parental genomes revealed strong maternal genome effects on bone wet weight (74.1%, p < 0.0001) and axial skeletal growth (93.5%, p < 0.001), whereas paternal genome controlled limb ossification (95.1%, p < 0.0001). Histomorphometric data revealed strong maternal genome effects on growth plate height (98.6%, p < 0.0001) and trabecular thickness (85.5%, p < 0.0001) in distal femur. Parental genome effects on fetal bone were mirrored by maternal genome effects on fetal serum 25‐hydroxyvitamin D (96.9%, p < 0.001) and paternal genome effects on alkaline phosphatase (90.0%, p < 0.001) and their correlations with maternally controlled bone wet weight and paternally controlled limb ossification, respectively. Bone wet weight and flat bone size correlated positively with muscle weight (r = 0.84 and 0.77, p < 0.0001) and negatively with muscle H19 expression (r = –0.34 and –0.31, p < 0.01). Because imprinted maternally expressed H19 regulates growth factors by miRNA interference, this suggests muscle‐bone interaction via epigenetic factors.

Atlas of tissue- and developmental stage specific gene expression for the bovine insulin-like growth factor (IGF) system

The insulin-like growth factor (IGF) axis is fundamental for mammalian growth and development. However, no comprehensive reference data on gene expression across tissues and pre- and postnatal developmental stages are available for any given species. Here we provide systematic promoter- and splice variant specific information on expression of IGF system components in embryonic (Day 48), fetal (Day 153), term (Day 277, placenta) and juvenile (Day 365–396) tissues of domestic cow, a major agricultural species and biomedical model. Analysis of spatiotemporal changes in expression of IGF1, IGF2, IGF1R, IGF2R, IGFBP1-8 and IR genes, as well as lncRNAs H19 and AIRN, by qPCR, indicated an overall increase in expression from embryo to fetal stage, and decrease in expression from fetal to juvenile stage. The stronger decrease in expression of lncRNAs (average ―16-fold) and ligands (average ―12.1-fold) compared to receptors (average ―5.7-fold) and binding proteins (average ―4.3-fold) is consistent with known functions of IGF peptides and supports important roles of lncRNAs in prenatal development. Pronounced overall reduction in postnatal expression of IGF system components in lung (―12.9-fold) and kidney (―13.2-fold) are signatures of major changes in organ function while more similar hepatic expression levels (―2.2-fold) are evidence of the endocrine rather than autocrine/paracrine role of IGFs in postnatal growth regulation. Despite its rapid growth, placenta displayed a more stable expression pattern than other organs during prenatal development. Quantitative analyses of contributions of promoters P0-P4 to global IGF2 transcript in fetal tissues revealed that P4 accounted for the bulk of transcript in all tissues but skeletal muscle. Demonstration of IGF2 expression in fetal muscle and postnatal liver from a promoter orthologous to mouse and human promoter P0 provides further evidence for an evolutionary and developmental shift from placenta-specific P0-expression in rodents and suggests that some aspects of bovine IGF expression may be closer to human than mouse.