ARTICLE Redefining “Virgin Birth” After Kaguya: Mammalian Parthenogenesis in Experimental Biology, 2004-2014
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ARTICLE Redefining “Virgin Birth” After Kaguya: Mammalian Parthenogenesis in Experimental Biology, 2004-2014 Eva Mae Gillis-Buck University of California, San Francisco [email protected] Abstract Virgin birth is a common theme in religious myths, science fiction, lesbian and feminist imaginaries, and sensational news stories. Virgin birth enters a laboratory setting through biologists’ use of the term parthenogenesis (Greek for virgin birth) to describe various forms of development without sperm. Scientific consensus holds that viable mammalian parthenogenesis is impossible; that is, mammalian embryos require both a maternal and a paternal contribution to develop completely. This essay investigates the historical development of that consensus and the evolving scientific language of parthenogenesis after the birth of Kaguya, a mouse with two mothers and no father. I qualitatively analyze 202 peer-reviewed scientific publications that cite the Kaguya experiment, and find unconventional interpretations of sex and parenthood, even in publications that maintain the impossibility of mammalian parthenogenesis. Though many scientists insist that males are necessary, they also describe eggs as paternal, embryos as sperm-free, and bimaternal sexual reproduction as something distinct from parthenogenesis. I argue that the scientific language used to explain the Kaguya experiment both supports a heteronormative reproductive status quo and simultaneously challenges it, offering bimaternal sexual Gillis-Buck, E.M. (2016). Redefining “Virgin Birth” After Kaguya: Mammalian Parthenogenesis in Experimental Biology, 2004-2014. Catalyst: Feminism, Theory, Technoscience, 2 (1), 1-67 http://www.catalystjournal.org | ISSN: 2380-3312 © Eva Mae Gillis-Buck, 2016 | Licensed to the Catalyst Project under a Creative Commons Attribution Non-Commercial No Derivatives license Gillis-Buck Catalyst: Feminism, Theory, Technoscience 2(1) 2 reproduction as a feasible alternative. Introduction In 2004, a group of Korean and Japanese scientists reported the birth of a healthy mouse with two mothers and no father. The scientists named the mouse Kaguya, after a Japanese folktale princess born from a bamboo stump, and published a Nature paper entitled “Birth of parthenogenetic mice that can develop to adulthood” (Kono et al., 2004). The word parthenogenesis, from the Greek for virgin birth, is a term scientists use to describe various forms of reproduction and development without sperm. Media headlines, such as “The End of Males?” and “Two Mums Make Baby,” fueled public interest in what Kaguya’s birth might mean for human reproduction (Fisher, 2004; Trivedi, 2004). But Tomohiro Kono, one of the leading scientists behind the Kaguya experiment, told reporters that the idea of human parthenogenesis was “senseless” (Ritter, 2004). Kono and colleagues argued that Kaguya’s birth actually demonstrated how and why males are required for mammalian reproduction. The Kaguya experiment, they explained, was simply an effort to better understand an epigenetic process called genomic imprinting and why the maternal and the paternal genome are both necessary for complete mammalian development. The idea that a mouse without a father could demonstrate the necessity of males seems contradictory, and ironic given the history of feminist and lesbian engagement with parthenogenesis. All-female reproduction has been a theme of feminist science fiction throughout the twentieth century (Ingram-Waters, 2006, 2008; Squier, 1994), and lesbian separatist groups in the 1970s and 1980s followed parthenogenesis research closely, optimistic for its potential as a new reproductive technology (Kelly, 1977; Rensenbrink, 2010). Scholars have noted that the actualization of a queer imaginary – parthenogenesis – has ironically been used as scientific support for the biological necessity of males, upholding a heteronormative one-father plus one-mother reproductive scheme (Ingram-Waters, 2006, 2008; Lafuente Funes, 2012; Rensenbrink, Gillis-Buck Catalyst: Feminism, Theory, Technoscience 2(1) 3 2010). However, in this paper, I show that unconventional interpretations of sex and parenthood can be found even in scientific research that claims mammalian parthenogenesis is impossible. Many scientists insist that males are necessary, but they also describe eggs as paternal, embryos as sperm-free, and bimaternal sexual reproduction as something distinct from parthenogenesis. Given the etymology of parthenogenesis, and the tendency of some scientists and media outlets to use parthenogenesis and virgin birth interchangeably, the language used to explain the Kaguya experiment contributes to scientific and cultural understandings of sex, gender, reproduction, and family. I argue that language of the Kaguya experiment both supports a reproductive status quo and simultaneously challenges it. To better understand how this scientific language has evolved, I first contextualize the Kaguya experiment within the history of parthenogenesis research, which is caught up in what I call a discourse of impossibility. I use this phrase to describe conversations among scientists, taking place in academic journals in the twentieth and twenty-first century, that conclude in a consensus: viable parthenogenesis in mammals is impossible, even though it is a common form of reproduction in many insect, reptile, and bird species. So-called parthenotes—eggs that begin dividing and developing without the contribution of sperm—were made into a routine laboratory technology, and the understanding that parthenotes could never develop to term made them the “right tools for the job” in many ways (Clarke & Fujimura, 1992). The inviability of mammalian parthenotes was useful to developmental biologists, who compared parthenotes with fertilized embryos to discover the necessary components of sperm in early development. Geneticists found parthenogenesis useful, given parthenotes’ haploid or homozygous diploid genome, which could reveal recessive mutations. Parthenotes were also key to the conceptualization of genomic imprinting in the 1980s. Then, in the early twenty-first century, parthenotes became a source of stem cells. At a time when American scientists could not use federal funding for the creation of human Gillis-Buck Catalyst: Feminism, Theory, Technoscience 2(1) 4 embryonic stem cell lines, human parthenogenetic stem cells served as an ethical alternative. Destroying a parthenote for stem cell derivation was not viewed as destroying a potential human life. This line of reasoning was largely dependent on the idea that mammalian parthenogenesis could never result in a live birth. Thus a productive experimental paradigm and strong political forces helped solidify the discourse of impossibility into a consensus: viable mammalian parthenogenesis does not and cannot happen. The rest of this paper examines how the birth of Kaguya—a healthy mammalian parthenote—affected the discourse of impossibility and the language used to describe gametes and reproduction. Using a data set of 202 peer-reviewed publications that cite the Kaguya experiment, I investigate how scientists interpreted the birth of a mouse with no father and used the words parthenogenesis, maternal, paternal, and bimaternal in their published articles. My focus on language continues a feminist tradition of paying close attention to word choice and metaphor in scientific descriptions of sperm and egg, nucleus and cytoplasm, gene and environment (Butler, 1990; Fausto-Sterling, 1989; Keller, 1995; Martin, 1991; Moore, 2007). The case of mammalian parthenogenesis is particularly well-suited for this type of analysis, given the loaded term virgin birth. Virgin birth is a common theme in religious myths, science fiction, lesbian and feminist imaginaries, and sensational news stories. Virgin birth enters a laboratory setting through biologists’ use of the term parthenogenesis, sometimes used interchangeably with virgin birth (Miyoshi et al., 2006; Wilmut, Campbell, & Tudge, 2000). For example, a 2002 Nature article on genomic imprinting and entitled “Immaculate Misconception” stated, “Sex is necessary and ‘virgin’ births are impossible in humans” (Surani, 2002, p. 491). By investigating scientists’ word choice when describing development without sperm, this essay contributes to discussions of how scientific narratives influence and are influenced by gender norms and cultural understandings of reproduction, sexuality, and family. Gillis-Buck Catalyst: Feminism, Theory, Technoscience 2(1) 5 PART 1: Establishing the impossibility of mammalian parthenogenesis In the twentieth and twenty-first centuries, biologists compared parthenotes with fertilized embryos to investigate the role of sperm in early development. By examining the historical use of parthenotes in experimental biology, we can better understand how the discourse of impossibility was built up over time and how Kaguya’s birth was interpreted within that discourse. 1.1 Artificial mammalian parthenogenesis. In the 1890s, German-American biologist Jacques Loeb developed a technique he called artificial parthenogenesis: inducing division and development in unfertilized sea urchin eggs by altering the salt concentration of seawater.1 American biologist Gregory Pincus—well known for his later work on oral contraceptives—claimed that “Loeb stopped too soon,” and Pincus hoped to bring about artificial parthenogenesis in mammals (quoted in Pauly, 1987, p. 187). In the 1930s and 1940s, Pincus experimented with Loeb’s methods and found