Genetics Topic: Application of Cloning to the Production of Biopharmaceuticals to Treat Human and Animal Disease

Health Care: Human & Animals

Nuclear Transfer – Cloning

Advantages

Proven methodology in several species, recent reports of success in Sheep, cattle & pigs

Good efficiency, < ~ 98% of offspring are transgenic, demonstrates stable transgene integration & expression

Germline transgenesis

Less costly due to transfection/selection in vitro

Disadvantages

Methodology not optimized in domestic animals

Strategies for “knockout” & “knockin” constructs

Table 1. Development of caprine embryos reconstructed by nuclear transfer using CFF6 transgenic fetal somatic cells

Nuclear transfer protocols	Metaphase II	Telophase II-Ca	Telophase II- EtOH
Oocytes reconstructed	138	92	55
Oocyte lysis (%)	67 (48.5)	38 (41.3)	23 (41.8)
Embryo cleavage (%)	48 (34.8)	41 (44.6)	31 (58.4)
Embryos transferred (%)	37 (34)	38 (41.3)	27 (49.1)
Recipients	15	14	9
Ultrasound positive (%) 30 days	9 (60)	11 (78.6)	5 (55.5)
40 days	1 (6.7)	1 (7.1)	0
60 days	1 (6.7)	1 (7.1)	0
Term pregnancy (%)	1 (6.7)	1 (7.1)	0
Offspring	1	2	0
% of embryos transferred	2.1	5.2	0
% of embryos reconstructed	0.7	2.2	0

Table 2. rhAT expression in CFF6-1 goat milk from an induced lactation

CFF6-1 induced Lactation day	hAT concentration (g/liter)	hAT activity (U/ml)
Day 3	4.7	N/D
Day 5	5.8	20.5
Day 6	5.0	18.3
Day 7	4.7	15.6
Day 8	4.1	14.4
Day 9	3.7	14.6
N/D: not determined

Summary

Rational application of animal cloning to the production of biopharmaceuticals
Benefit to human and animal health
Animal welfare is not compromised
Advance fundamental understanding of mechanism that regulate normal and abnormal cell growth

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