Publications by category
Journal articles
Appleby SJ, Misica-Turner P, Oback FC, Dhali A, McLean ZL, Oback B (2022). Double cytoplast embryonic cloning improves <i>in vitro</i> but not <i>in vivo</i> development from mitotic pluripotent cells in cattle.
FRONTIERS IN GENETICS,
13 Author URL.
McLean ZL, Appleby SJ, Fermin LM, Henderson HV, Wei J, Wells DN, Oback B (2021). Controlled Cytoplast Arrest and Morula Aggregation Enhance Development, Cryoresilience, and <i>In Vivo</i> Survival of Cloned Sheep Embryos.
CELLULAR REPROGRAMMING,
23(1), 14-25.
Author URL.
McLean ZL, Appleby SJ, Wei J, Snell RG, Oback B (2021). Front Cover Image, Volume 88, Issue 1, January 2021. Molecular Reproduction and Development, 88(1).
McLean ZL, Appleby SJ, Wei J, Snell RG, Oback B (2020). Testes of <i>DAZL</i> null neonatal sheep lack prospermatogonia but maintain normal somatic cell morphology and marker expression.
Molecular Reproduction and Development,
88(1), 3-14.
Abstract:
Testes of DAZL null neonatal sheep lack prospermatogonia but maintain normal somatic cell morphology and marker expression
AbstractMultiplying the germline would increase the number of offspring that can be produced from selected animals, accelerating genetic improvement for livestock breeding. This could be achieved by producing multiple chimaeric animals, each carrying a mix of donor and host germ cells in their gonads. However, such chimaeric germlines would produce offspring from both donor and host genotypes, limiting the rate of genetic improvement. To resolve this problem, we disrupted the RNA‐binding protein DAZL and generated germ cell‐deficient host animals. Using Cas9‐mediated homology‐directed repair (HDR), we introduced a DAZL loss‐of‐function mutation in male ovine fetal fibroblasts. Following manual single cell isolation, 4/48 (8.3%) of donor cell strains were homozygously HDR‐edited. Sequence‐validated strains were used as nuclear donors for somatic cell cloning to generate three lambs, which died at birth. All DAZL null male neonatal sheep lacked germ cells on histological sections and showed greatly reduced germ cell markers. Somatic cells within their testes were morphologically intact and expressed normal levels of lineage‐specific markers, suggesting that the germ cell niche remained intact. This extends the DAZL mutant phenotype beyond mice into agriculturally relevant ruminants, providing a pathway for using absolute germline transmitters in rapid livestock improvement.
Abstract.
McLean Z, Appleby SJ, Wei J, Snell RG, Oback B (2019). Testes of <i>DAZL</i> null sheep lack spermatogonia and maintain normal somatic cells.
Abstract:
Testes of DAZL null sheep lack spermatogonia and maintain normal somatic cells
AbstractMultiplying the germline would increase the number of offspring that can be produced from selected animals, accelerating genetic improvement for livestock breeding. This could be achieved by producing multiple chimaeric animals, each carrying a mix of donor and host germ cells in their gonads. However, such chimaeric germlines would produce offspring from both donor and host genotypes, limiting the rate of genetic improvement. To resolve this problem and produce chimaeras with absolute donor germline transmission, we have disrupted the RNA-binding protein DAZL and generated germ cell-deficient host animals. Using Cas9 mediated homology-directed repair (HDR), we introduced a DAZL loss-of-function mutation in male ovine fetal fibroblasts. Following manual single-cell isolation, 4/48 (8.3%) of donor cell strains were homozygously HDR-edited. Sequence-validated strains were used as nuclear donors for somatic cell cloning to generate three lambs, which died at birth. All DAZL-null male neonatal sheep lacked germ cells. Somatic cells within their testes were morphologically intact and expressed normal levels of somatic cell-specific marker genes, indicating that the germ cell niche remained intact. This extends the DAZL-mutant phenotype beyond mice into agriculturally relevant ruminants, providing a pathway for using absolute transmitters in rapid livestock improvement.
Abstract.
Publications by year
2022
Appleby SJ, Misica-Turner P, Oback FC, Dhali A, McLean ZL, Oback B (2022). Double cytoplast embryonic cloning improves <i>in vitro</i> but not <i>in vivo</i> development from mitotic pluripotent cells in cattle.
FRONTIERS IN GENETICS,
13 Author URL.
2021
McLean ZL, Appleby SJ, Fermin LM, Henderson HV, Wei J, Wells DN, Oback B (2021). Controlled Cytoplast Arrest and Morula Aggregation Enhance Development, Cryoresilience, and <i>In Vivo</i> Survival of Cloned Sheep Embryos.
CELLULAR REPROGRAMMING,
23(1), 14-25.
Author URL.
McLean ZL, Appleby SJ, Wei J, Snell RG, Oback B (2021). Front Cover Image, Volume 88, Issue 1, January 2021. Molecular Reproduction and Development, 88(1).
2020
Zachariah McLean Z, J Appleby S, M Fermin L, Oback B (2020). Generating cloned sheep embryos by zona-free somatic cell transfer v1.
Abstract:
Generating cloned sheep embryos by zona-free somatic cell transfer v1
This protocol summarises zona-free sheep cloning by somatic cell transfer (SCT), adapted from a similar SCT method in cattle (https://doi.org/10.1089/153623003772032763). It describes the workflow that is required for reprogramming somatic cells into cloned blastocysts of high morphological quality, including two optional steps of embryo aggregation and vitrification. The resulting embryos can then be transferred into surrogate ewes for producing live cloned animals. Compared to conventional zona-intact procedures, this zona-free embryo reconstruction system increases throughput of cloned embryo production and ease of operation.
Abstract.
McLean ZL, Appleby SJ, Wei J, Snell RG, Oback B (2020). Testes of <i>DAZL</i> null neonatal sheep lack prospermatogonia but maintain normal somatic cell morphology and marker expression.
Molecular Reproduction and Development,
88(1), 3-14.
Abstract:
Testes of DAZL null neonatal sheep lack prospermatogonia but maintain normal somatic cell morphology and marker expression
AbstractMultiplying the germline would increase the number of offspring that can be produced from selected animals, accelerating genetic improvement for livestock breeding. This could be achieved by producing multiple chimaeric animals, each carrying a mix of donor and host germ cells in their gonads. However, such chimaeric germlines would produce offspring from both donor and host genotypes, limiting the rate of genetic improvement. To resolve this problem, we disrupted the RNA‐binding protein DAZL and generated germ cell‐deficient host animals. Using Cas9‐mediated homology‐directed repair (HDR), we introduced a DAZL loss‐of‐function mutation in male ovine fetal fibroblasts. Following manual single cell isolation, 4/48 (8.3%) of donor cell strains were homozygously HDR‐edited. Sequence‐validated strains were used as nuclear donors for somatic cell cloning to generate three lambs, which died at birth. All DAZL null male neonatal sheep lacked germ cells on histological sections and showed greatly reduced germ cell markers. Somatic cells within their testes were morphologically intact and expressed normal levels of lineage‐specific markers, suggesting that the germ cell niche remained intact. This extends the DAZL mutant phenotype beyond mice into agriculturally relevant ruminants, providing a pathway for using absolute germline transmitters in rapid livestock improvement.
Abstract.
2019
McLean Z, Appleby SJ, Wei J, Snell RG, Oback B (2019). Testes of <i>DAZL</i> null sheep lack spermatogonia and maintain normal somatic cells.
Abstract:
Testes of DAZL null sheep lack spermatogonia and maintain normal somatic cells
AbstractMultiplying the germline would increase the number of offspring that can be produced from selected animals, accelerating genetic improvement for livestock breeding. This could be achieved by producing multiple chimaeric animals, each carrying a mix of donor and host germ cells in their gonads. However, such chimaeric germlines would produce offspring from both donor and host genotypes, limiting the rate of genetic improvement. To resolve this problem and produce chimaeras with absolute donor germline transmission, we have disrupted the RNA-binding protein DAZL and generated germ cell-deficient host animals. Using Cas9 mediated homology-directed repair (HDR), we introduced a DAZL loss-of-function mutation in male ovine fetal fibroblasts. Following manual single-cell isolation, 4/48 (8.3%) of donor cell strains were homozygously HDR-edited. Sequence-validated strains were used as nuclear donors for somatic cell cloning to generate three lambs, which died at birth. All DAZL-null male neonatal sheep lacked germ cells. Somatic cells within their testes were morphologically intact and expressed normal levels of somatic cell-specific marker genes, indicating that the germ cell niche remained intact. This extends the DAZL-mutant phenotype beyond mice into agriculturally relevant ruminants, providing a pathway for using absolute transmitters in rapid livestock improvement.
Abstract.