Different intervals of ovum pick-up affect the competence of oocytes to support the preimplantation development of cloned bovine embryos.

The objective of this study was to determine the effect of different frequencies of transvaginal ovum pick-up (OPU) on the quantity of recovered cumulus oocyte complexes (COCs) and subsequently the competence of matured oocytes to support the preimplantation development of cloned bovine embryos. The COCs were aspirated from the ovaries of 6 Chinese Holstein cows by transvaginal follicle aspiration twice a week (every 3 or 4 days) (Group I), every 5 days (Group II), once a week (every 7 days) (Group III), every 10 days (Group IV), and once every 2 weeks (every 14 days) (Group V). The developmental stages of the follicles were confirmed by the diameter of the dominant follicle (DF) and harvested COCs, and the dynamics of the follicular wave were clarified.

[Reconstruction of embryo using an improved nuclear transfer method].

Previous methods used for nuclear transplantation were further investigated to develop a method that was both easy to carryout and did not require any special apparatus, such as Piezoimpact or Spindle-View. Following the puncture of zona pellucida with two holes by injection pipette that contained donor nuclei or cells, the injection pipette was pulled back to the perivitelline space while the negative pressure was increased in the holding pipette until the polar body and karyoplasm were wiped off completely. Then a reconstructed embryo was completed by the direct injection of the donor nucleus or cell without pulling out the injection pipette.

[Knockout serum replacement improves establishment efficiency of C57BL/6J mouse embryonic stem cell line].

Aim: To eliminate the influence of serum on self-renewal of embryonic stem cells (ESCs), knockout serum replacement (KSR), a defined formulation, was used to replace serum for the establishment of C57BL/6J mouse ESC line.

Methods: C57BL/6J mouse blastocysts collected at 3.5 days post coitum (d.

Factors derived from mouse embryonic stem cells promote self-renewal of goat embryonic stem-like cells.

Goat embryonic stem (ES)-like cells could be isolated from primary materials-inner cell masses (ICMs) and remain undifferentiated for eight passages in a new culture system containing mouse ES cell conditioned medium (ESCCM) and on a feeder layer of mouse embryo fibroblasts (MEFs). However, when cultured in medium without mouse ESCCM, goat ES-like cells could not survive for more than three passages. In addition, no ES-like cells could be obtained when ICMs were cultured on goat embryo fibroblasts or the primary materials-whole goat blastocysts were cultured on MEFs.

Efficient differentiation of embryonic stem cells into neurons in glial cell-conditioned medium under attaching conditions.

Embryonic stem (ES) cells can differentiate into neurons in vitro, which provides hope for the treatment of some neurodegenerative diseases through cell transplantation. However, it remains a challenge to efficiently induce ES cells to differentiate into neurons. Here, we show that murine ES cells can efficiently differentiate into neurons when cultured in glial cell-conditioned medium (GCM) under attaching conditions without the formation of embryoid bodies.

Dopamine D(4) receptor antagonist 3-(4-[(18)F]fluorobenzyl)-8-methoxy-1,2,3,4-tetrahydrochromeno[3,4-c]pyridin-5-one([(18)F]FMTP): radiosynthesis and in vivo characterization in rats.

We synthesized a novel (18)F-labeled dopamine D(4) receptor antagonist (Ki=4.3 nM), 3-(4-[(18)F]fluorobenzyl)-8-methoxy-1,2,3,4-tetrahydrochromeno[3,4-c]pyridin-5-one ([(18)F]FMTP), which has exhibited high affinity and selectivity. Radiosyntheses were accomplished by the reaction of fluorine-18-labeled intermediate with 8-methoxy-1,2,3,4-tetrahydrochromeno[3,4-c]pyridin-5-one (1) followed by HPLC purification.