Annual Report 2006

Fig. 6
Birth weight of 11 adult SNT clones
Red characters indicate individuals with bi-allelic expression of imprinting gene(s).
Blue characters indicate those with mono-allelic ones.
Green circle and yellow square indicate average birth weight of female and male artificially inseminated(AI).
Japanese black SNT clones. Surprisingly,
almost half of healthy and well-grown adult
bovine SNT clones had imprinting disorder, i.e.
bi-allelic expressions. Some of them were also
confirmed fertile. These results were clearly
indicated that imprinting disorder was common
for bovine SNT clones with no apparent
abnormality in adulthood. But our further
analysis revealed the relationship between
overweight at birth and bi-allelic disorder (Fig.
6). Our results indicate that the management of
imprinting will crucial for effective SNT clone
reproduction.
Protein-permeable scaffold of a
collagen vitrigel membrane
useful for reconstructing
crosstalk models between two
different cells
We recently succeeded in converting a soft
andturbiddiskofcollagengelintoastrongand
transparent gel-membrane by utilizing a concept
for the vitrification of heat-denatured proteins
and named the novel gel in a stable condition
for vitrigel. The collagen vitrigel membrane
involving a nylon frame can be easily handled
with tweezers, consequently it functions as a
scaffold excellent for three-dimensionally
culturing cells on double surfaces of it. Here, we
investigated the molecular permeability of the
collagen vitrigel membrane in time-course
using glucose and serum proteins. The glucose
added to one compartment penetrated into
another compartment via the collagen vitrigel
membrane and the glucose concentration of
each compartment came nearly up to a plateau
level within 24 hours. Serum proteins with not
only low molecular weight but also high one
more than 100 kDa passed gradually through
the collagen vitrigel membrane (Fig. 7). These
Fig. 7
Permeability tests in time-course for the collagen vitrigel membrane using glucose and serum proteins
Change of glucose concentration (A), quantitative clearance of FBS (B), and qualitative clearance of FBS (C) were
estimated using the samples at the indicated times.