The aim of this article is to demonstrate and characterize caprine mammary epithelial cells (CMC)... more The aim of this article is to demonstrate and characterize caprine mammary epithelial cells (CMC) immortalized with human telomerase reverse transcriptase (hTERT) gene. Five immortalized CMCs were assigned to either myoepithelial or luminal epithelial groups based on their morphology and expression of cell lineage-specific intermediate filaments. Telomeric repeat amplification protocol revealed various telomerase activities in CMCs associated with their distinct proliferation potential. Karyotypic analysis showed three CMCs retained their modal Capra hircus chromosome number (2n = 60), whereas the remaining two CMCs were abnormal at 2n = 19 and 2n = 36. CMCs with abnormal karyotypes lost p53 protein after chemical-induced DNA damage and showed anchorage-independent growth in soft agar assay. In terms of functional differentiation, luminal CMCs organized into alveolus-like structures when grown in Matrigel. Furthermore, αs1- and β-casein gene was induced in luminal CMCs in response to lacto-hormones stimulation. Together these results showed that hTERT-immortalized CMCs retained major characteristics of mammary epithelial cells, and stability of the genome is required for maintaining normal mammary epithelium function. Application of CMCs can provide valuable models to study alveologenesis and lactogenesis of mammary epithelium and test the feasibility of recombinant constructs designed for the generation of transgenic livestock.
Goat β-casein (CSN2) promoter has been extensively used to derive expression of recombinant thera... more Goat β-casein (CSN2) promoter has been extensively used to derive expression of recombinant therapeutic protein in transgenic goats; however, little direct evidence exists for signaling molecules and the cis-elements of goat CSN2 promoter in response to lactogenic hormone stimulation in goat mammary epithelial cells. Here, we use an immortalized caprine mammary epithelial cell line (CMC) to search for evidence of the above. Serial 5'-flanking regions deleted of promoter and intron 1 in goat CSN2 (-4,047 to +2,054) driven by firefly luciferase reporter gene were constructed and applied to measure promoter activity in CMC. The intron 1 region (+393 to +501) significantly decreased basal activity of the promoter. This finding contradicts other studies of the role of intron 1. The signal transducer and activator of transcription (STAT)5a played a significant role in activating promoter activity by prolactin stimulation. Hydrocortisone enhanced and prolonged the activity of STAT5a an...
Elucidating how demography and contemporary landscape features regulate functional connectivity a... more Elucidating how demography and contemporary landscape features regulate functional connectivity and diversity is crucial to implementing effective conservation strategies, especially in highly fragmented landscapes. We analyzed the impacts of landscape features and demographic events on the dispersal and genetic structure of a locally endangered carnivore, the leopard cat (Prionailurus bengalensis), across subtropical Taiwan. We genotyped 184 samples from both human-impacted and natural habitats using 12 nuclear microsatellites and a mitochondrial marker. Bayesian analyses revealed a recent population decline within the past 200 years, and a current genetic hotspot appears to have arisen from interbreeding between previously diverged populations. Genetic clustering and resistance surface modeling support the notion that the population structure is influenced by manufactured linear and natural topographical features. We employed a landscape optimization procedure using two genetic di...
The aim of this article is to demonstrate and characterize caprine mammary epithelial cells (CMC)... more The aim of this article is to demonstrate and characterize caprine mammary epithelial cells (CMC) immortalized with human telomerase reverse transcriptase (hTERT) gene. Five immortalized CMCs were assigned to either myoepithelial or luminal epithelial groups based on their morphology and expression of cell lineage-specific intermediate filaments. Telomeric repeat amplification protocol revealed various telomerase activities in CMCs associated with their distinct proliferation potential. Karyotypic analysis showed three CMCs retained their modal Capra hircus chromosome number (2n = 60), whereas the remaining two CMCs were abnormal at 2n = 19 and 2n = 36. CMCs with abnormal karyotypes lost p53 protein after chemical-induced DNA damage and showed anchorage-independent growth in soft agar assay. In terms of functional differentiation, luminal CMCs organized into alveolus-like structures when grown in Matrigel. Furthermore, αs1- and β-casein gene was induced in luminal CMCs in response to lacto-hormones stimulation. Together these results showed that hTERT-immortalized CMCs retained major characteristics of mammary epithelial cells, and stability of the genome is required for maintaining normal mammary epithelium function. Application of CMCs can provide valuable models to study alveologenesis and lactogenesis of mammary epithelium and test the feasibility of recombinant constructs designed for the generation of transgenic livestock.
Goat β-casein (CSN2) promoter has been extensively used to derive expression of recombinant thera... more Goat β-casein (CSN2) promoter has been extensively used to derive expression of recombinant therapeutic protein in transgenic goats; however, little direct evidence exists for signaling molecules and the cis-elements of goat CSN2 promoter in response to lactogenic hormone stimulation in goat mammary epithelial cells. Here, we use an immortalized caprine mammary epithelial cell line (CMC) to search for evidence of the above. Serial 5'-flanking regions deleted of promoter and intron 1 in goat CSN2 (-4,047 to +2,054) driven by firefly luciferase reporter gene were constructed and applied to measure promoter activity in CMC. The intron 1 region (+393 to +501) significantly decreased basal activity of the promoter. This finding contradicts other studies of the role of intron 1. The signal transducer and activator of transcription (STAT)5a played a significant role in activating promoter activity by prolactin stimulation. Hydrocortisone enhanced and prolonged the activity of STAT5a an...
Elucidating how demography and contemporary landscape features regulate functional connectivity a... more Elucidating how demography and contemporary landscape features regulate functional connectivity and diversity is crucial to implementing effective conservation strategies, especially in highly fragmented landscapes. We analyzed the impacts of landscape features and demographic events on the dispersal and genetic structure of a locally endangered carnivore, the leopard cat (Prionailurus bengalensis), across subtropical Taiwan. We genotyped 184 samples from both human-impacted and natural habitats using 12 nuclear microsatellites and a mitochondrial marker. Bayesian analyses revealed a recent population decline within the past 200 years, and a current genetic hotspot appears to have arisen from interbreeding between previously diverged populations. Genetic clustering and resistance surface modeling support the notion that the population structure is influenced by manufactured linear and natural topographical features. We employed a landscape optimization procedure using two genetic di...
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