At CS10-CS11, the aortic sac was located at the ventral pharyngeal mesenchyme
. The aortic sac wall was composed of endothelium and mesenchyme
and was a-SMA and MHC negative [Figure 1]a and [Figure 1]b.
The embryonic development of submandibular salivary glands of mouse begins at embryonic day 11 (E 11).9 The oral epithelium is separated by the underlying neural crest cell-derived mesenchyme
(ectomesenchyme) by a sheet of extracellular matrix.10 It is reported that development and maintenance of salivary glands is dependent upon reciprocal coordination between epithelium and mesenchymal interactions.11
However, this is challenged by a latest case report with intact thoraco-acromial arteries and muscle fascia, suggesting an alternative theory of paraxial mesenchyme
developmental failure (5).
In the present study, we have successfully cloned the sequence of full coding region of Vps26A gene in the reserve mesenchyme
of antler tip samples, and studied the expression levels in different growth periods.
Follicular mesenchymal cells used in this study consisted of two populations isolated from median (Med) and lateral mesenchyme
(Lat) of feather follicles, accordingly.
Disturbance in tooth development where abnormal tissue interactions between the oral epithelium and the underlying mesenchyme
occurring during development may result in ectopic tooth development.
(1,2) Several theories like primitive cartilage forming mesenchyme
, chondroblastic differentiation, synovial intimal cells, past surgical or traumatic insult, inhalation of chemical carcinogens, (1) multiple hereditary exostoses, intravenous thorotrast, previous irradiation, Maffucci syndrome, and Ollier disease (4) have been postulated, but none has been considered satisfactory.
Hattori (2) suggested that the cysts may be derived from misplaced mesothelium and mesenchyme
with Mullerian characteristics similar to retroperitoneal Mullerian cysts.
We counted the number of osteoclasts only at the suture mesenchyme
of the sagittal suture in all slides according to the method in our previous work .
The antler tip, composed of a velvet skin, perichondrium, mesenchyme
, and chondroprogeniors, was taken using sterilized surgical instruments and then mesenchyme
was obtained by slices of tissues.
The origin and pathogenesis of angiolipomas remain unknown while pluripotential mesenchymal stem cells , congenital malformation, benign hamartoma , and primitive mesenchyme
 could be associated with its specific entity.