Nuclear Transfer in the Mouse

AbstractCloning, through somatic cell nuclear transfer (SCNT), has the potential for a large expansion of genetically favorable traits in a population in a relatively short term. In the present study we aimed to produce multiple cloned camels from racing, show and dairy exemplars. We compared several parameters including oocyte source, donor cell and breed differences, transfer methods, embryo formation and pregnancy rates and maintenance following SCNT. We successfully achieved 47 pregnancies, 28 births and 19 cloned offspring who are at present healthy and have developed normally. Here we report cloned camels from surgical embryo transfer and correlate blastocyst formation rates with the ability to achieve pregnancies. We found no difference in the parameters affecting production of clones by camel breed, and show clear differences on oocyte source in cloning outcomes. Taken together we demonstrate that large scale cloning of camels is possible and that further improvements can be achieved.

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Two Novel Cases of Autosomal Translocations in the Horse: Warmblood Family Segregating t(4;30) and a Cloned Arabian with a de novo t(12;25)

Cytogenetic and Genome Research ◽

10.1159/000512206 ◽

2020 ◽

Vol 160 (11-12) ◽

pp. 688-697

Author(s):

Sharmila Ghosh ◽

Candice F. Carden ◽

Rytis Juras ◽

Mayra N. Mendoza ◽

Matthew J. Jevit ◽

...

Keyword(s):

Somatic Cell Nuclear Transfer ◽

Nuclear Transfer ◽

Congenital Abnormalities ◽

Assisted Reproductive Technologies ◽

De Novo ◽

Reproductive Technologies ◽

Balanced Translocation ◽

Translocation Breakpoints ◽

Normal Offspring ◽

Embryonic Death

We report 2 novel autosomal translocations in the horse. In Case 1, a breeding stallion with a balanced t(4p;30) had produced normal foals and those with congenital abnormalities. Of his 9 phenotypically normal offspring, 4 had normal karyotypes, 4 had balanced t(4p;30), and 1 carried an unbalanced translocation with tertiary trisomy of 4p. We argue that unbalanced forms of t(4p;30) are more tolerated and result in viable congenital abnormalities, without causing embryonic death like all other known equine autosomal translocations. In Case 2, two stallions produced by somatic cell nuclear transfer from the same donor were karyotyped because of fertility issues. A balanced translocation t(12q;25) was found in one, but not in the other clone. The findings underscore the importance of routine cytogenetic screening of breeding animals and animals produced by assisted reproductive technologies. These cases will contribute to molecular studies of translocation breakpoints and their genetic consequences in the horse.

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Robotic Precisely Oocyte Blind Enucleation Method

Applied Sciences ◽

10.3390/app11041850 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1850

Author(s):

Xiangfei Zhao ◽

Maosheng Cui ◽

Yidi Zhang ◽

Yaowei Liu ◽

Xin Zhao

Keyword(s):

Success Rate ◽

Nuclear Transfer ◽

Operation Time ◽

Volume Control ◽

Translation Control ◽

Cleavage Rate ◽

Training Time ◽

Manual Method ◽

Control Oocyte ◽

Key Techniques

Oocyte enucleation is a critical procedure for somatic cell nuclear transfer. Yet, the main steps of oocyte enucleation are still manually operated, which presents several drawbacks such as low precision, high repetition error, and long training time for operators. For improving the operation efficiency and success rate, a robotic precise oocyte blind enucleation method is presented in this paper. The proposed method involves the following key techniques: oocyte translation control, oocyte immobilization and penetration control, and enucleation volume control based on the adaptive slide mode. Compared with the manual blind enucleation method, the proposed robotic blind enucleation method reduced the operation time by 44.5% (manual method: 62 s vs. proposed method: 34.4 s), increased the accuracy of enucleation by 83.1% (manual method: 30.7 vs. proposed method: 5.2), increased the success rate from 80% to 93.3%, and increased the cleavage rate from 41.7% to 63.3%.

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