Scope and Application of Stem Cell Research in Livestock

Jayanti Tokas1, Puneet Tokas2, Shailini Jain3, Hariom Yadav3

1Department of Biotechnology, JMIT, Radaur, Haryana, India

2KITM, Kurukshetra, Haryana, India3NIDDK, National Institute of Health, Bethesda, MD 20892,

USAEmail: yadavhariom@gmail.com

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

TelomereNo shortening of telomere in stem cells

DNA MethylationMinimum 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 1995 Bovine culturing embryo derived cells resemble epithelial cells rather than pluripotent ICM cells

Talbot et al 2000 Bovine embryonic cells grew as cell sheets. Passaging by physical dissociation

Li et al 2003 Porcine 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 2005 ES cells from cloned bovine embryos with marker staining

pattern similar to bovine blastocystsYadav 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 - 5 TPA Ovine - 4 Alpha AT Pigs - 2 AT III Rabbits - 7 Alpha glucosidase