Scope and Application of Stem Cell Research in Livestock Jayanti Tokas 1, Puneet Tokas 2, Shailini Jain 3, Hariom Yadav 3 1 Department of Biotechnology, JMIT, Radaur, Haryana, India 2 KITM, Kurukshetra, Haryana, India 3 NIDDK, National Institute of Health, Bethesda, MD 20892, USA

Stem Cell Stem cells are master cells with two important characteristics Unspecialized cells capable of their own renewal Ability to differentiate into different cell types The stem cells may have various differentiation potentials Totipotent Pluripotent Multipotent Unipotent

Types of stem cells Embryonic stem cells Adult stem cells

Characteristics of Embryonic stem cells Derived from ICM/epiblast of Blastocyst Pluripotent Long-term self-renewal Exibit and maintain a stable diploid normal complement of chromosome Expression of Oct-4 Lacks G1 check point in the cells cycle Don’t show X inactivation

Stemness Genes Oct4 Nanog SSEA1 SSEA2 SSEA3 BMP4

Characteristics of Adult stem cells Long-term self-renewal Give rise to mature cells having characteristic morphologies and specialized functions Rare Dispersed in tissues throughout the body Origin of adult stem cells in tissues is yet not known

Tissues containing adult stem cells Bone marrow Skeletal muscle Epithelia of skin and digestive system Cornea retina Peripheral blood Spinal cord Blood vessels Testes Liver Pancreas Kidney Heart, etc

Stem cells speciality Apoptosis No apoptosis in stem cells Telomere No shortening of telomere in stem cells DNA Methylation Minimum DNA methylation in stem cells

ES cells from livestock species Iwaski et al 1990 ICM proportion lower in bovine IVF embryos than in vivo produced Saito et al 1992 Bovine embryonic stem cells grow slower than murine embryonic stem cells Hamers et al 1995Bovine culturing embryo derived cells resemble epithelial cells rather than pluripotent ICM cells Talbot et al 2000Bovine embryonic cells grew as cell sheets. Passaging by physical dissociation Li et al 2003Porcine ICMs isolated by enzymatic method. Two embryonic cell lines cultured upto 6 passages van Eijk et al 1999 Bovine Oct 4 pseudogene isolated Wang et al 2005ES cells from cloned bovine embryos with marker staining pattern similar to bovine blastocysts Yadav et al 2005 Bovine ICM derived cells express the Oct4 ortholog

Major Applications Animal model testing for pharmaceutical research Use of stem cells in transplantation and cell replacement therapy Conservation of endangered species Understanding fundamental events in embryonic development Therapeutic delivery system To resolve mysteries of developmental biology To investigate genes involved in differentiation and development Cell banking for research applications

Identification of stem cells Cell morphology Expression of unique cell surface antigens Characterization of biochemical markers such as tissue specific enzymatic activity Expression of genes that are unique to a particular cell type Nuclear chromosomal karyotype to access genetic stability

Scope Pharmaceuticals: diabetes, cardiac anomalies, neurodegeneration, and infertility Neutraceuticals : produce heterologous nutrients Understanding early embryonic development Model for in vitro drug and immunity screening Producing environment friendly animals eg. Phytase and methane Tissue remodeling and engineering Cell-cell communication and differentiation Conservation Germ stem cells challenge age old dogma of female born with fixed number of oocytes

Livestock stem cells Farm animals are contributing in human health through Nutrition Producing biomedicine Cell therapy Xenotransplantation With decoding of the genome sequences in animals, stem cell promise to resolve many mysteries of the developmental biology

Transgenic animals with important agricultural traits  Bovine alpha lactalbumin in mammary glands of sows–improves lactation performance  Sheep carrying Kerartin – IGF-1 construct shows expression in skin for clear fleece in transgenic animals  Transgenic pig bearing an hMt-pGH construct tightly regulated by Zinc feeding - improves traits as growth rate, feed conversion, body fat muscle ratio  Phytase gene exclusively expressed in salivary gland enables the pigs to digest phytate which can be metabolized by the intestine. Release low phosphorus in manure

Transgenic in Biomedicine Proteins synthesized in farm animals milk Bovine - 2 Human lactoferrin Caprine - 5TPA Ovine - 4Alpha AT Pigs - 2AT III Rabbits - 7Alpha glucosidase