Primary culture and maintenance of steroid-secreting human placental monolayers

Summary A simple method is described for primary culture and for maintenance of hormone-producing cells from normal human placenta. A consistent yield of cells was obtained and an average survival of 3 to 4 months in culture using 1 mm³ explants from the most vascular area of the placentas. These explants were placed in a variety of culture media in 30 ml flasks and incubated at 37°C in an atmosphere of 5% CO₂ and 95% air. The best yields in terms of cell growth were observed with Eagle’s MEM (minimum essential medium) with supplements of horse serum and fetal calf serum or human cord serum. (Ham’s F-10 with supplement of horse serum and fetal calf serum supports growth for the longest period and media containing human cord serum had the best yield of steroids.) Presented in part at the 25th meeting of the Tissue Culture Association, June 5, 1974, Miami Beach, Florida. Supported by a contract from the Agency for International Development (2491/csd) and a grant from the National Institutes of Health (CA-12455).     

Requirement of serum components for the preservation of primordial germ cells in testis cords during early stages of testicular differentiation in vitro in the mouse

Mouse gonadal primordia were isolated from embryos on the 11th day of gestation and cultured in vitro. They developed into either testes or ovaries after 7 days of culture in Eagle's minimum essential medium (MEM) supplemented with horse serum, whereas they did not differentiate in MEM alone. We studied how serum components are required for testicular development in vitro. When gonadal primordia were cultured in MEM alone for the first 1-3 days and subsequently in MEM supplemented with serum, testis cords developed while germ cells disappeared or only a few remained in the testis cords. In contrast, when serum was present in the medium during the first day of culture and omitted thereafter, germ cells were retained within testis cords. These results suggested that some serum component(s) is specifically required by germ cells independent of testis cord organization. Of more than 10 serum components tested, low and very low density lipoprotein fractions increased the number of germ cells in testicular explants.     

Interactions of indole acetic acid with EGF and FSH in the culture of ovine preantral follicles

The mechanisms that regulate the gradual exit of ovarian follicles from the non-growing, primordial pool are very poorly understood. The objective of this study was to evaluate the effects of adding indole acetic acid (IAA), epidermal growth factor (EGF) and follicle stimulating hormone (FSH) to the media for in vitro culture of ovine ovarian fragments and determine their effects on growth activation and viability of preantral follicles. The ovarian cortex was divided into small fragments; one fragment was immediately fixed in Bouin (control). The other fragments were cultured for 2 or 6 days in culture plates with: minimum essential medium (MEM) supplemented with insulin-transferrin-selenium (ITS), pyruvate, glutamine, hypoxantine, bovine serum albumine and antibiotics (MEM+); MEM+ plus IAA (40 ng/mL); MEM+ plus EGF (100 ng/mL); MEM+ plus FSH (100 ng/mL); MEM+ plus IAA+EGF; MEM+ plus IAA+FSH; MEM+ plus EGF+FSH; or MEM+ plus IAA+EGF+FSH. After 2 or 6 days of culture in each treatment, the pieces of ovarian cortex were fixed in Bouin for histological examination. Follicles were classified as primordial or developing (primary and secondary) follicles. Compared to the control, in all media tested, the percentages of primordial follicles were reduced (P<0.05) and the percentages of developing follicles were increased (P<0.05) after 2 or 6 days of culture. Furthermore, culture of ovarian cortex for 6 days reduced the percentages of healthy, viable follicles when compared with the control (P<0.05), except for cultures supplemented with IAA+EGF and EGF+FSH. In conclusion, the addition of IAA and EGF or EGF and FSH to the culture media were the most effective treatments to sustain the health and viability of activated ovine primordial follicles during in vitro culture.     

Growth of mouse vaginal epithelial cells in culture: Effect of sera and supplemented serum-free media

Summary Normal mouse vaginal epithelial cells isolated from ovariectomized ca. 35-d-old BALB/cCrgl mice were grown in primary culture using collagen gel metrix and a serum-free medium composed of a 1∶1 mixture of Dulbecco’s modified Eagle’s medium and Ham’s F12 (D:H) medium supplemented with insulin (IN), epidermal growth factor (EGF), cholera toxin, transferrin, and bovine serum albumin V (BSA). Three-dimensional cellular outgrowths occurred inside the collagen gel matrix. The contribution of each factor to cell growth was examined by individual addition to the basic D:H medium and by individual deletion from the complete serum-free medium. When added individually, only IN promoted growth. Deletion of IN from the complete serum-free medium markedly, diminished growth; deletion of EGF or BSA slightly diminished growth. When horse, fetal bovine, or chicken serum was added to the basal D:H medium, only with increasing doses of horse serum was there enhanced cell growth. The effect of 17?-estradiol and diethylstilbestrol on the growth of cells was also tested, using a suboptimal medium of D:H supplemented with BSA and IN, or a minimal medium supplemented with IN alone. During the 8-d time period, addition of estrogen did not enhance cell growth in either medium. To date, we have been unable to demonstrate a mitogenic effect of estrogen; rather a dose-dependent inhibition of proliferation is seen. This investigation was supported by grants CA-05388 and CA-09041, awarded by the National Institutes of Health, DHHS, Bethesda, MD.     

Direct somatic embryogenesis from pericycle cells of broccoli (Brassica oleracea L. var. italica) root explants

Cotyledon, hypocotyl or root explants of 7-day-old broccoli seedlings were cultured on Murashige and Skoog (MS) agar or liquid medium supplemented with 1.0 mg l⁻¹ 2,4-dichlorophenoxyacetic acid (2,4-D). The frequency of direct somatic embryo formation was 100% when root explants were cultured in liquid medium. Histological analysis indicated that somatic embryos were initiated directly from the pericycle cell layers of root explants as early as 1 day after liquid culture. Genotype did not affect the frequency of somatic embryo formation or the number of somatic embryos per explant. All broccoli genotypes examined had 100% somatic embryo induction efficiency, and the number of somatic embryos per 0.8 mm root segment ranged from 22.9 in ‘Luhui’ to 26.0 in ‘Haizi’. The number of normally developed somatic embryos in culture increased with increasing 2,4-D concentration. Plantlet regeneration frequency was the highest (73.3%) when germinated plantlets were transferred to 1/2 strength MS agar medium containing 1.0 mg l⁻¹ 6-benzyladenine (BA). When regenerated plantlets were transferred to a greenhouse, approximately 75% survived and there were no morphological differences between regenerated plants and seed-derived controls. The protocols established in this study will benefit large-scale vegetative propagation and transformation-based genetic improvement of broccoli.     

Efficient plant regeneration via somatic embryogenesis and organogenesis from the explants of <Emphasis Type="Italic">Catharanthus roseus</Emphasis>

High-frequency plant regeneration of C. roseus cv. ‘little bright eye’ via somatic embryogenesis and organogenesis from five out of six explants was standardized. Two factors were found to be important for regeneration: (1) the type of explants, and (2) the combination and concentrations of plant growth regulators. The highest regeneration percentage through somatic embryogenesis was obtained from mature zygotic embryo in MS medium supplemented with 7.5 μM of thidiazuron (TDZ). The mature embryo also regenerated efficiently via organogenesis in MS medium supplemented with either 2.5 μM TDZ or 5.3 μM α-naphthalene acetic acid (NAA) and 2.2 μM 6-benzylaminopurine (BA). Hypocotyl and cotyledon did not induce somatic embryogenesis and organogenesis in TDZ-containing medium but gave a maximum percentage of shoots in MS medium supplemented with 5.3 μM NAA and 2.2 μM BA. Stem nodes and meristem tips showed better regeneration via organogenesis in the medium supplemented with NAA and BA and in lower concentrations of TDZ.     

Effects of ascorbic acid on in vitro culture of bovine preantral follicles

Summary The objective of this study was to evaluate the effects of adding ascorbic acid to the media for in vitro culture of cattle ovarian fragments and to determine their effects on growth activation and viability of early-stage follicles. The ovarian cortex was divided into small fragments; one fragment was immediately fixed (control) and the other fragments were cultured in minimum essential medium (MEM) supplemented or not with various doses of ascorbic acid. Ovarian tissue was processed for histology, transmission electron microscopy (TEM) and immunohistochemical demonstration of proliferating cell nuclear antigen (PCNA). Compared with control fragments, the percentage of primordial follicles was reduced (p < 0.05) and the percentage of growing follicles had increased (p < 0.05) in cultured cortical fragments, independent of the tested medium or incubation time. Furthermore, compared with control tissue, culture of ovarian cortex for 8 days reduced the percentages of healthy, viable follicles (p < 0.05), but not when cultures were supplemented with 25, 50 or 100 μg/ml of ascorbic acid. Ultrastructural and immunohistochemical analysis of 8 day cultured ovarian cortical fragments, however, showed the integrity and viability of follicles only when fragments were cultured in presence of 50 μg/ml of ascorbic acid. In conclusion, this study demonstrated that addition of ascorbic acid to MEM at a concentration of 50 μg/ml not only stimulates the activation of 8 day in vitro cultured cattle primordial follicles and subsequent growth of activated follicles, but also safeguards the viability of these early-stage follicles.     

Use of cyanobacterial gas vesicles as oxygen carriers in cell culture

The gas vesicles isolated from the cells of filamentous cyanobacterium Anabaena flos-aquae were treated and sterilized with glutaraldehyde and then evaluated for their effectiveness as gas carriers in cell culture. Anchorage-dependent Vero cells were grown in a packed bed of microcarrier beads under the perfusion of Dulbecco’s Modified Eagle’s Medium with 1% serum. The culture medium supplemented with 1.8% (v/v) gas vesicles was found to support a 30% higher maximum glucose utilization rate than the same medium without gas vesicles. The gas vesicle suspension was confirmed to have no apparent effects on cell metabolism in T-flask cultures. The study results indicated that the gas vesicles, with high oxygen carrying capacity, can be used to increase the oxygen supply in cell culture systems.     

Essential role of follicle stimulating hormone in the maintenance of caprine preantral follicle viability in vitro

The aims of the present study were to investigate the effects of follicle-stimulating hormone (FSH) on survival, activation and growth of caprine primordial follicles using histological and ultrastructural studies. Pieces of caprine ovarian cortex were cultured for 1 or 7 days in minimum essential medium (MEM - control medium) supplemented with different concentrations of FSH (0, 10, 50 or 100 ng/ml). Small fragments from non-cultured ovarian tissue and from those cultured for 1 or 7 days in a specific medium were processed for classical histology and transmission electron microscopy (TEM). Additionally, effects of FSH on oocyte and follicle diameter of cultured follicles were evaluated. The results showed that the lowest percentage of normal follicles was observed after 7 days of culture in control medium. After 1 day of culture, a higher percentage of growing follicles was observed in the medium supplemented with 50 ng/ml of FSH. In the presence of 10 and 50 ng/ml of FSH, an increase in diameter of both oocyte and follicle on day 7 of culture was observed. TEM showed ultrastructural integrity of follicles after 1 day of culture in MEM and after 7 days in MEM plus 50 ng/ml FSH, but did not confirm the integrity of those follicles cultured for 7 days in MEM. In conclusion, this study demonstrated that FSH at concentration of 50 ng/ml not only maintains the morphological integrity of 7 days cultured caprine preantral follicles, but also stimulate the activation of primordial follicles and the growth of activated follicles.     

Cell-mediated contraction of collagen lattices in serum-free medium: Effect of serum and nonserum factors

Summary This study was conducted to identify a defined, serum-free culture medium that supports cell dependent contraction of a collagen lattice. Collagen lattices were found to contract in cultures containing human foreskin fibroblasts (HFF) or rabbit aortic smooth muscle (RASM) cells incubated in serum-free medium. HFF and RASM cells required different supplements to contract the collagen gels. HFF cultured in Dulbecco’s modified Eagle’s (DME) medium supplemented with bovine serum albumin (BSA) and either endothelial cell growth supplement (EnGS), insulin (In), or platelet derived growth factor (PDGF) supported collagen lattice contraction. Replacement of BSA with casein without the addition of other supplements improved contraction. In contrast, RASM cells supplemented with BSA, EnGS, In, and PDGF were able to contract collagen gels only minimally. Similar to HFF, RASM cells cultured in DME medium supplemented with casein, but without the addition of other supplements, contracted collagen lattices. HFF-mediated collagen contraction was inhibited by prostaglandins E₁ or E₂, fibronectin, or ascorbic acid. The reported serum-free model provides a useful in vitro method to investigate the role of serum and nonserum factors regulating cell mediated-contraction of insoluble collagen fibrils. Presented in part as abstract 1963 in the 1985 Federation of American Societies for Experimental Biology, April 21–26, Anaheim, California, and published in Fed. Proc. (44):747; 1985.     

Culture of fetal alveolar epithelial type II cells in serum-free medium

Summary A serum-free culture medium (defined medium = DM) was elaborated by adding to Eagle’s minimum essential medium (MEM), non-essential amino acids, transferrin, putrescine, tripeptide glycyl-histidyl-lysine, somatostatin, sodium selenite, ethanolamine, phosphoethanolamine, sodium pyruvate, and metal trace elements. This medium was tested for its ability to support sustained surfactant biosynthesis in fetal alveolar epithelial type II cells. For up to 8 days, ultrastructure was maintained with persistance of lamellar inclusion bodies. Thymidine incorporation into DNA was enhanced about 50% in DM as compared with MEM, whereas it was enhanced 300% in 10% fetal bovine serum. With DM, the incorporation of tritiated choline into phosphatidylcholine (PC) of isolated surfactant material was about twice that with MEM. Deletion experiments evidenced the prominent role of pyruvate, transferrin, and selenium in the stimulation of surfactant PC biosynthesis. The addition of biotin to DM enhanced surfactant PC biosynthesis slightly and nonsurfactant PC biosynthesis markedly. The presence of nucleosides seemed unfavorable to the synthesis of surfactant PC. Type II cells responded to the addition of epidermal growth factor and insulinlike growth factor-I both by increased thymidine incorporation into DNA and choline incorporation into PC. It is concluded that DM represents a useful tool for cultivating type II cells without loss of their specialized properties and for studying the regulation of cell proliferation and surfactant biosynthesis in a controlled environment.     

Serum-free organ culture of suckling rat jejunum: Effect of regulatory hormones

Summary To facilitate the study of regulators of differentiation and proliferation of small intestinal epithelium in the suckling rat we have developed a serum-free organ culture system and used it to examine epithelial responsiveness to various regulatory hormones. These hormones included the insulin-like growth factors (IGFs) whose action can be blocked by binding proteins in serum. Jejunal explants from 5-day-old suckling rats maintained better brush border enzyme activity and better histology when cultured under hyperbaric conditions for 24 h in serum-free Dulbecco’s modified Eagle’s medium/F12 medium than in RPMI 1640 plus 10% fetal bovine serum. Tissue responsiveness to various regulatory hormones was then tested in the serum-free medium. Insulin had no significant effect on morphology, proliferation rate, or enzyme activity in 5-day explants after 24 h in culture. However, insulin did increase lactase activity and induce the early appearance of sucrase in 10- and 12-day explants after 48 h culture. Dexamethasone increased specific activities of alkaline phosphatase (30%,P<0.001) and lactase (15%,P<0.001), and reduced shedding of alkaline phosphatase into the medium (P<0.001), in explants of 5-day-old rats cultured over 24 h. Dexamethasone combined with insulin had no obvious effect on the rate of protein or DNA synthesis but did increase villus height (P=0.04) and crypt depth (P=0.001) and acted synergistically to further increase lactase activity above levels obtained by either alone. IGF-I and IGF-II, des-(1–3)IGF-I, fibroblast growth factor (FGF), and growth hormone (GH) had no effect on morphology or biochemical activity of explants after 24 or 48 h culture. In conclusion, histology, enzyme activity, protein, and DNA synthesis of suckling rat jejunal explants were equivalent or better in serum-free than in serum-containing organ culture systems. Furthermore, biological responsiveness was demonstrated by dexamethasone and insulin altering the explants morphologically or biochemically. None of the IGFs or GH had any biological effects, raising doubts about their direct biological action on the developing intestinal epithelium.     

Factors affecting plantlet regeneration from <Emphasis Type="Italic">in vitro</Emphasis> cultured immature embryos and cotyledons of <Emphasis Type="Italic">Prunus mume</Emphasis> “Xue mei”

Using immature embryos and cotyledons as explants, a successful system to culture immature embryos and induce direct regeneration from cotyledons was established for Prunus mume “Xuemei”. For immature embryo culture, a high frequency of plantlet formation (89.5%) from the embryonic axis was obtained using half-strength Murashige and Skoog (1/2 MS) medium supplemented with 13.2 μM 6-benzyladenine (BA) and 2.7 μM 1-naphthaleneacetic (NAA). Shoots formed directly from cotyledons with the embryo axis intact when explants were cultured on 1/2 MS medium containing 2.2 μM BA with different combinations of NAA (2.7, 5.4 μM) and indole-3-butyric acid (IBA) (0, 2.5, 5.0 μM). Better results were achieved when the embryonic axis was removed from the cotyledons and cultured on 1/2 MS medium supplement with 13.2 μM BA, 2.7 μM NAA or 2.2 μM BA, 2.2 μM thidiazuron (TDZ), and 2.7 μM NAA, respectively. Regenerated shoots were successfully rooted on 1/2 MS or Woody Plant medium (WPM) supplemented with 2.5–5.0 μM IBA. The effect of the embryonic axis, BA, and TDZ on cotyledon regeneration was investigated in detail. Rooted plantlets were transferred to soil successfully.     

Efficient plant regeneration through direct somatic embryogenesis from leaf explants of <Emphasis Type="Italic">Phalaenopsis</Emphasis> ‘Little Steve’

Summary Leaf segments of the orchid sp. Phalaenopsis ‘Little Steve’ were used as explants testing the effects of 2,4-dichlorophenoxyacetic acid (2,4-D; 0.45, 2.26, 4.52 μM), 6-furfurylaminopurine (kinetin; 2.32, 4.65, 13.95 μM), N⁶-benzyladenine (BA; 2.22, 4.44, 13.32 μM), and 1-phenyl-3-(1,2,3-thiadiazol-5-yl)-urea (TDZ; 2.27, 4.54, 13.62μM) on the induction of direct somatic embryogenesis. After 20–30 d of culture in darkness, clusters of somatic embryos formed from leaf surfaces and wounded regions of explants on half-strength Murashige and Skoog medium supplemented with BA and TDZ. However, kinetin had no response on direct embryo induction. In addition, 2,4-D highly retarded the frequency of embryogenesis that was induced by TDZ. Generally, adaxial surfaces near wounded regions had the highest embryogenic competency compared to other regions of explants. Histological sections revealed that somatic embryos mostly arose from epidermal cell layers of the explants. Secondary embryogenesis occurred at basal parts of embryos, and originated from outer cell layers. Following transfer of regenerated embryos onto growth regulator-free medium for 3.5–4 mo., plantlets with three to four leaves and several roots were obtained. This protocol provides a simple way to regenerate plants through direct somatic embryogenesis, and is suitable for further studies on embryo development and genetic transformation of Phalaenopsis.     

Effect of oocyte maturation medium on in vitro development of in vitro fertilized bovine embryos.

The objective of this study was to examine the effects of different culture media used for maturation of bovine oocytes on in vitro embryo development following in vitro fertilization. Oocytes were aspirated from 2-5 mm follicles of ovaries collected at a local abattoir. The oocyte-cumulus complexes (OCCs) were cultured for 23-25 h in one of seven commercially available media supplemented with 6 mg/ml bovine serum albumin (BSA), 0.25 mM pyruvate, 10 micrograms/ml luteinizing hormone (LH), 0.5 microgram/ml follicle-stimulating hormone (FSH), and 1 microgram/ml estradiol. After maturation for 23-25 h, all eggs were subjected to the same in vitro fertilization protocol using modified TALP medium and subsequently cultured in the same serum-free embryo culture medium (HECM-1/BSA) for 8 days, after which embryo development was assessed. Five media (SFRE, MEM alpha, TCM199, MEM alpha/+, RPMI:MEM alpha) better supported normal oocyte maturation as determined by embryo development to the two-cell (76-82%), morula/blastocyst (25-32%), and blastocyst (12-19%) stages. Oocytes that were matured in Waymouth's medium MB 752/l or Ham's F-12 had a significantly reduced incidence of cleavage to the two-cell stage (52% and 37%, respectively), which was not attributed to failure of fertilization. Of the eggs that did cleave to the two-cell stage in these two media, 27% and 9% developed to morulae/blastocysts but only 6% and 3%, respectively, developed into blastocysts.(ABSTRACT TRUNCATED AT 250 WORDS)     

The use of somatic embryogenesis for plant propagation in cassava

In cassava, somatic embryogenesis starts with the culture of leaf explants on solid Murashige and Skoog-based medium supplemented with auxins. Mature somatic embryos are formed within 6 wk. The cotyledons of the primary somatic embryos are used as explants for a new cycle of somatic embryogenesis. The cotyledons undergo secondary somatic embryogenesis on both liquid and solid Murashige and Skoog-based medium supplemented with auxins. Depending on the auxin, new somatic embryos are formed after 14–30 d after which they can be used for a new cycle of somatic embryogenesis. In liquid medium, more than 20 secondary somatic embryos are formed per initial cultured embryo. In both primary and secondary somatic embryogenesis, the somatic embryos originate directly from the explants. Transfer of clumps of somatic embryos to a Greshoff and Doy-based medium supplemented with auxins results in indirect somatic embryogenesis. The direct form of somatic embryogenesis has a high potential for use in plant propagation, whereas the indirect has a high potential for use in genetic modification of cassava. Mature somatic embryos germinate into plants after desiccation and culture on a Murashige and Skoog-based medium supplemented with benzylaminopurine (BA). Depending on the used BA concentration, plants can either be transferred either directly to the greenhouse or after using standard multiplication protocols.     

Effects of growth medium and cyclic AMP analogues on the cAMP-induced differentiation of F9 teratocarcinoma cells

Summary F9 teratocarcinoma cells differentiate into parietal endodermlike cells when treated with retinoic acid (RA) and cyclic AMP (cAMP). We have previously found that F9 cells can be induced to differentiate by treatment with cAMP in the absence of RA. In the course of determining why other investigators had failed to observe cAMP-induced differentiation, we found that the growth medium played an important role in determining the response of F9 cells to differentiating agents. When F9 cells were grown in minimal essential medium (MEM) and treated with either 8-bromo-cAMP (8BrcA) + 1-methyl, 3-isobutylxanthine (MIX), or dibutyryl cAMP (DBcA) + theophylline (T), they differentiated to parietal endodermlike cells without any requirement for exogenous RA. However, when F9 cells were grown in Dulbecco’s modified Eagle’s medium (DME), DBcA/T failed to induce differentiation alone and required exogenous RA to induce formation of parietal endoderm-like cells. 8BrcA/MIX alone was still able to induce some differentiation, although the extent was not as great as those cells grown in MEM. These results could not be explained by the different growth-promoting properties of the two culture media because there was no difference in the doubling time of F9 cells grown in either medium. Likewise, RA and cAMP both inhibited growth to the same extent in either medium. Inasmuch as almost all published reports on F9 cell differentiation have used DME as a growth medium, and RA with or without DBcA/T as the differentiating agents, these studies would not have had the appropriate conditions to detect the cAMP-induced differentiation of F9 cells.     

Characterization of a rat anterior pituitary cell bioassay

Summary We have described the protocols and characterization of a pituicyte culture, which became established as a reliable and reproducible bioassay for the secretion of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The bioassay was used to measure the bioactivity of factors that inhibit and stimulate gonadotrophin secretion. The protocol that was used involved the culling of female Wistar rats (200 to 250 g weight), at random stages of their cycle, and dispersal of their pituicytes in a concentration of 0.4 × 10⁶ cells · ml⁻¹ · well⁻¹ in serum-free medium (Dulbecco’s modified Eagle’s medium/Ham’s F12 mixture, supplemented with insulin and transferrin) in Falcon 3047 24-well culture plates. After 24 h of pre-culture, the medium was changed and the cells cultured for a further 48 h. The supernatant was removed and assayed for basal secretion of FSH and LH. The cells were then stimulated with 10⁻⁸ M GnRH for 4 h and the supernatant assayed for gonadotrophin-releasing hormone (GnRH)-stimulated FSH and LH secretion. All samples were assayed as pairs of duplicates (i.e. quadruplicate samples) which were randomly added to the plates to minimize plate effects. Random number tables were used to achieve this randomization.     

Plant Regeneration from Immature Embryo Cultures of Vigna unguiculata

Micropropagated plants of two annual haloxerophytic Asiatic Salsola species (S. pestifer and S. lanata) were obtained from zygotic embryos cultured on Murashige and Skoog (MS) agar medium supplemented with 0.5 μM benzylamino-purine (BAP) and 0.3 μM indole-3-acetic acid (IAA) or with 0.5 μM 6 γ, γ-dimethylallylaminopurine and 0.3 μM IAA. The callus induction from shoot and leaf explants derived from plants propagated in vitro were obtained on MS agar medium with various concentration of auxins and cytokinins. The best medium for growth and proliferation of calluses of both studied species was MS medium containing 9.0 μM 2,4-dichlorophenoxyacetic acid. It was also determined that beginning of plant regeneration from callus of S. lanata was induced by 8.8 μM BAP. This revised version was published online in July 2006 with corrections to the Cover Date.     

Cultivation of epithelia from the secretory coil of the ovine apocrine gland: Evidence of secretory cell function and ductal morphogenesis In vitro

Summary The secretory coil of the ovine apocrine gland is composed predominantly of two cell types, secretory cells lining the lumen and myoepithelial cells adjacent to the basement membrane. The glands synthesize a number of hormones and growth factors, but analysis of the functions of these molecules may be hampered by the mixing of apocrine and sebaceous secretions in the pilary canal. The purpose of this study was to isolate the glands and devise simple culture procedures to facilitate investigations of secretory cell function. The most successful approach involved microdissection of the secretory coils individually from skin biopsies and culture in Dulbecco’s modified Eagle’s medium. After 1–2 wk in medium, cell outgrowths were seen from explants. These consisted predominantly of populations of epithelial cells, many containing granules. Smaller granules were usually concentrated around the cell nuclei and accumulated lipophilic dyes. Large granules were unreactive. Western analysis showed that cells in culture synthesized nerve growth factor-like peptides, a feature consistent with one of the functions of the gland in vivo. When isolated secretory coils were explanted to culture dishes coated with matrigel, highly compact, multilayered masses of cells grew out. Subsequently, tubular structures formed. The observations suggest that some differentiated functions of gland cells were retained in vitro and that the procedures described provide a system for the study of apocrine secretions in isolation from those of other skin glands.