Sejvar J J, Landis S C, Hall A K
Department of Neuroscience, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106.
Dev Biol. 1993 Jun;157(2):547-52. doi: 10.1006/dbio.1993.1157.
Sympathetic neurons, chromaffin cells, and small, intensely fluorescent (SIF) cells are thought to derive from a common sympathoadrenal precursor cell. Sympathoadrenal precursor cells and adrenal chromaffin cells have been shown to react with an antibody, SA-1; we now report that, like sympathoadrenal precursors, SIF cells during their proliferative phase transiently possess this epitope. Precursors and SIF cells were identified in double-label studies of the superior cervical ganglion (SCG) using SA-1 and an antibody that identifies a noradrenergic trait, tyrosine hydroxylase (TH). At E16 when the earliest SIF precursors were detected and at birth, while postmitotic principal neurons had lost SA-1 reactivity, many SIF cells expressed both TH and SA-1. As development proceeded, the proportion of SIF cells expressing only TH increased. In addition, some small SIF-like cells possessed only SA-1 reactivity at birth. Some SIF cells at P7 possessed SA-1, but it was absent at P10 and in the adult. Bromodeoxyuridine (BrdU) was used to identify proliferating SIF cells, and SA-1+ expression was correlated with the period of SIF cell proliferation. At late embryogenesis, the proportion of SA-1+ SIF cells that possessed BrdU was relatively large (17% at E20), and decreased as SIF cell division ceased (6% at P1). Our results indicate that SA-1 is present on SIF cells when these cells are capable of cell division. In addition, mature SIF cells lack SA-1 and are therefore antigenically distinct from the sympathoadrenal precursor. These data suggest that the expression of SA-1 is correlated with the ability of sympathoadrenal cells to proliferate, in the SCG early during embryogenesis, chromaffin cells both during embryogenesis and in the adult, and SIF cells during their transient period of division in the SCG.
交感神经元、嗜铬细胞和小而强荧光（SIF）细胞被认为起源于共同的交感肾上腺前体细胞。交感肾上腺前体细胞和肾上腺嗜铬细胞已被证明能与抗体SA - 1发生反应；我们现在报告，与交感肾上腺前体细胞一样，SIF细胞在其增殖期短暂地具有这种表位。在上颈神经节（SCG）的双标记研究中，使用SA - 1和一种识别去甲肾上腺素能特性的抗体酪氨酸羟化酶（TH）来鉴定前体细胞和SIF细胞。在胚胎第16天检测到最早的SIF前体细胞时以及出生时，有丝分裂后的主要神经元已失去SA - 1反应性，而许多SIF细胞同时表达TH和SA - 1。随着发育的进行，仅表达TH的SIF细胞比例增加。此外，一些小的SIF样细胞在出生时仅具有SA - 1反应性。一些P7的SIF细胞具有SA - 1，但在P10和成年时不存在。溴脱氧尿苷（BrdU）用于鉴定增殖的SIF细胞，SA - 1 +表达与SIF细胞增殖期相关。在胚胎发育后期，具有BrdU的SA - 1 + SIF细胞比例相对较大（E20时为17%），随着SIF细胞分裂停止而降低（P1时为6%）。我们的结果表明，当SIF细胞能够进行细胞分裂时，SA - 1存在于SIF细胞上。此外，成熟的SIF细胞缺乏SA - 1，因此在抗原性上与交感肾上腺前体细胞不同。这些数据表明，SA - 1的表达与交感肾上腺细胞的增殖能力相关，在胚胎早期的SCG中、胚胎期和成年期的嗜铬细胞以及SCG中SIF细胞的短暂分裂期均如此。
